1904 To 1971
18 March 1904
Sank off Isle of Wight after collision with SS Berwick Castle
On Friday March 18 1904, whist on exercise off the Isle of Wight HMS A1 was tasked with "attacking" HMS Juno . The mock attack began in the early afternoon; HMS Juno had been sighted heading towards Portsmouth Harbour. First to attack were the Holland Boats, after which came A1 's turn. As A1 closed in for the kill she was struck on the starboard side, near the conning tower, by the steam ship Berwick Castle , on route from Southampton to Hamburg. Unaware of the submarines in the area the master of the Berwick Castle reported that he believed he had been struck by a practice torpedo and continued his journey. It was not until A1 failed to return to harbour that the full scale of the disaster was known.
16 February 1905
Internal explosion
A5 experienced an internal petrol explosion shortly after refuelling from the depot ship HMS HAZARD berthed in Queenstown, County Cork. The cause of the explosion was petrol fumes being ignited by a spark from the Main Motor Brushes
5 June 1905
Sank in Plymouth Sound after internal explosion
At 1030 on the morning of 5th June an explosion ripped through HMS A8 whilst she was on exercise in Plymouth Sound. A nearby Trawler, the Chanticleer witnessed the explosion and lowered her boats as the submarine began to founder to offer assistance. Shortly after the submarine sank further explosions were witnessed and wreckage drifted to the surface. HMS A8 was salvaged on the 12 th and inspections indicated that the explosions were more than likely caused by a chemical reaction within the battery.
16 October 1905
Sank in Portsmouth Harbour
Whilst carrying out sound signal experiments at Spithead, HMS A4 was trimming down when water came through a ventilator being used to signal, with a flag on a boathook, the results of the sound tests.
The submarine went down to 90 feet with an inclination of 40 degrees by the bow. Due to the contact with seawater, chlorine gas started escaping from the batteries. The Captain ordered all ballast tanks blown and as soon as the submarine surfaced, the crew were ordered on deck. An explosion occurred as the boat was being towed to the dock and she slowly sank. She was later salved and put back into service.
14 July 1909
Sank in English Channel after collision with SS Eddystone
"Secretary to the Admiralty regrets having to communicate that Messrs Farrar, Groves, & Co's Steamer Eddystone, bound for Hull, was in collision with submarine C11 at 1145 last night, 4 miles north west of Haisborough Light, off Cromer and the submarine was sunk"
On 14 July 1909 whilst exercising off Cromer HMS C11 was struck aft by the steamer Eddystone. The collision had the stern clean off the submarine, which sank within 40 seconds. All but three of her crew were lost.
2 February 1912
Sank off Isle of Wight after collision with HMS Hazard
"The Commander-in-Chief regrets to announce that owing to a collision between His Majesty's Ship Hazard and the submarine A3, the latter sank near East Princess Buoy about noon today. It is feared that the submarine was completely flooded, in which case there is very little hope of the officers and crew being saved, though salvage appliances have been sent out."
Whilst on exercise off the Isle of Wight HMS A3 surfaced directly in the path of HMS Hazard . The collision caused a large hole to be torn in the side of the submarine sinking her almost immediately.
4 October 1912
Sank off Dover after collision with SS Amerika
In the early hours of 4 October HMS B2 was on the surface about four miles north east of Dover when the 23,000-ton steamer SS Amerika, on passage from Hamburg to New York, via Southampton, collided with the submarine. B2 was struck just forward of the conning tower: - a fatal blow that sent the submarine immediately to the bottom.
10 December 1913
Sank off Plymouth Sound after collision with Hopper
On the evening of the 10 th of December HMS C14, en route to Plymouth, when she collided with Government Hopper No 27 in Plymouth Sound. The submarine immediately began to take in large amounts of water and began sinking by the stern. The collision took place within sight of land from where help soon arrived and although the submarine sank within ten minutes, there were no casualties. HMS C14 was later salvaged and returned to active service.
8 June 1913 Internal explosion
An explosion occurred inside E5's Main Engines, resulting in the death of one Officer and two men. In addition, nine men were badly burned.
16 January 1914
Sank in Whitsand Bay near Plymouth
Whilst carrying out practice torpedo attacks against HM Ships Onyx and Pigmy, HMS A7 failed to surface having been seen to submerge by HMS Pigmy at 1110 The cause of her loss is not known and although her wreck was located on the 22 nd of January bad weather prevented salvage.
14 September 1914
Lost off New Britain (unknown cause)
On the 14 th September 1914 Australian Submarine AE1 , with a mixed crew of both British and Australian submariners, began a patrol of St Georges Straits accompanied by the Destroyer HMAS Parramatta . Visual contact between the two vessels was lost at around 1530. After which the submarine was not seen again. No claim of her sinking was ever made by Germany and no wreckage was found.
18 October 1914
Sunk off Borkum Island by U27
HMS E3 left Harwich on the 16 th October 1914 to patrol an area off Borkum. At the same time U27 was patrolling off the mouth of the Ems. At 1025 on the morning of 18 October U27 sighted E3 on the surface and was able to approach unobserved firing her torpedoes at a range of approximately 300 yards. The resulting explosion broke E3 in half and sent her immediately to the bottom.
3 November 1914
Mined off Yarmouth
On the 3 rd November 1914 a force of German battle cruisers commenced bombarding the town of Lowestoft. HM Submarines D3 , D5 and E10 were ordered to intercept the enemy off Terschelling. While proceeding on the surface to the interception point, D5 struck a drifting mine and was sunk.
25 November 14
Lost off Borkum Island
On the 23 rd November whilst returning to Yarmouth, in heavy seas, D2 's Captain, Lieutenant Commander A G Jameson was swept overboard and lost.
The following day D2 once again put to sea, this time under the command of Lieutenant Commander C Head. The submarine failed to return. It is believed that she was sunk on, or around, the 25 th of November, following an encounter with a German Torpedo Boat.
4 January 1915
Presumed mined off Belgian coast
C31 sailed from Dover on the 4 th January 1915 to patrol off Zeebrugge. The submarine was due to arrive at Harwich on 7 th January, which she failed to do. No further contact was made and a search conducted by the Destroyers Lercher and Firedrake and the Royal Navy Air Service failed to locate the submarine or any survivors.
18 January 1915
Possibly mined off Heligoland Bight
On the 18 th January HMS E10 sailed from Harwich for operations NNW of Heligoland. No further contact was made with the submarine after parting company with HMS E5 at 1950 on the evening of the 18 th . It is believed that E10 was destroyed by an enemy mine.
17 April 1915
Ran aground in Dardanelles
On 17 th April 1915 whilst attempting to run beneath the minefields guarding the Dardanelle Straits, HMS E15 was swept ashore by the strong currents. The submarine ran aground directly under the guns of Fort Dardanus. E15 came under heavy fire from the fort: - one shell killing the Captain, another hitting the vessels battery compartment forcing the crew to surrender. Many attempts were made to prevent the submarine falling into enemy hands and finally a torpedo launched from a picket boat put pay to Turkish attempts to re-float the submarine.
30 April 1915
Scuttled in Sea of Marmara
Whilst heading for a rendezvous with HMS E14 the Australian submarine AE2 encountered the Turkish torpedo boat Sultan Hisar . Having dived to avoid the torpedo boat, AE1 began an uncontrollable ascent to the surface, appearing a hundred yards from the torpedo boat.
AE2 submerged yet again this time in an uncontrollable dive. By going full astern the submarine once again surfaced only to come under fire from the torpedo boat. Once again the submarine entered an uncontrollable dive and once again full astern brought her to the surface. The Turks were waiting and a shell pierced the submarine around the engine room. No longer able to dive, the captain ordered all hands on deck and began scuttling the submarine.
4 August 1915
Probably mined in the North Sea
HMS C33 had been operating with the trawler Malta in an attempt to entice German submarines into attacking the trawler. C33 would be towed behind the trawler ready to attack any German vessel that closed to take a look. Having completed the patrol C33 and Malta parted company at 2015. The last contact with the submarine was a wireless message at 2150. No further contact was made and a search failed to locate any wreckage or survivors. The Germans made no claims for her sinking and it is therefore believed that the submarine must have hit a mine.
19 August 1915
Ran aground off Danish coast
Just after 2300 on 17 th August 1915 a faulty compass forced HMS E13 aground on a mud bank in Danish Territorial waters. All attempts to re-float the submarine failed and by the dawn of the 19 th both German and Danish vessels were in the area. Under International Law a belligerent warship is allowed sanctuary in neutral waters for up to 24 hours. At 0500 on the 19 th E13 was informed by the Danish ship Narvalen that she had 24 hours within which to re-float. With previous attempts having failed E13 attempted to gain a tow from the Danish vessels in the area. At 0928 two German destroyers were seen to be closing at high speed and flying the signal "Abandon Ship Immediately" The destroyers opened fire with torpedoes and machine guns. The crew of E13 who were resting on the casing were caught unawares and immediately abandoned the submarine and headed for the Danish ships and Internment.
29 August 1915
Mined in North Sea
On 29 th August 1915 HMS C29 and the trawler Ariadne were carrying out anti U-boat duties off the Outer Dowsing Light Vessel off the Humber in the North Sea. The submarine was under tow and in telephone contact with the trawler when the mine exploded.
4 September 1915
Scuttled at A/S Nets in Dardanelles
At 0700 on 4 th September 1915 HMS E7 dived to 100 feet in an attempt to break through the anti-submarine nets at Nagara Point in the Dardanelles. The attempt failed when the starboard propeller became entangled in the nets. All attempts to free the vessel failed and drew the attention of the Turkish craft in the area. After successive attacks E7 was forced to surface. Once the crew had been removed to safety, the vessel was scuttled.
6 November 1915
Torpedoed in Sea of Marmara by UB14
On 30 th October 1915 the French submarine Turquoise ran aground near Nagara Point, in the Dardanelles. With the submarine directly under the Turkish shore batteries the French crew hastily abandoned ship. Unfortunately for E20 , who was due to rendezvous with the Turquoise , the French Captain had failed to destroy his confidential papers. The Germans now knew of the rendezvous and despatched UB 14 to intercept the unsuspecting E20 . UB14 first sighted E20 at 1600 on the 6 th November, and 1700 at a range of 550 yards she fired a single torpedo scoring a direct hit.
26 December 1915
Mined off Harwich
On 26 th December 1915 HMS E6 left Harwich to carry out an anti-submarine patrol in the North Sea. As the submarine neared the Sunk Light Vessel she was signalled by a patrolling torpedo boat to keep clear. E6 continued on her course and within view of the torpedo boat struck a mine and disappeared.
6 January 1916
Scuttled off Texel Island after striking submerged rock
Whilst patrolling north of Texel Island on Thursday 6 th January 1916, HMS E 17 struck an uncharted sandbank. Badly damaged the submarine was forced to surface. The Royal Netherlands Navy Cruiser Noord Brabant approached the stricken submarine to investigate. E17 believing the Cruiser was belligerent submerged, but owing to the damage was forced to surface again. E1 signalled the un-identified cruisers for assistance and her crew were taken off and interned. E17 finally sank at 1140 on Thursday 6 th January 1916.
19 January 1916
Ran aground off Ameland Island (No loss of life)
On 18 th January H6 ran aground off the island of Schiermonikoog. A boat from the destroyer Firedrake brought off 2 officers, 10 men and the ship's papers. The remainder of the crew, including C.O., were rescued by the Dutch and interned at Groningen. The Dutch pulled H6 off the sands a month later. The submarine was sold to the Royal Netherlands Navy in February 1916, renamed O8 , and taken over by the German Navy during WW II for use as a training boat.
8 June 1913
An explosion occurred inside E5 's Main Engines, resulting in the death of one Officer and two ratings in addition: nine men were badly burned.
7 March 1916
Possibly lost off Western EMS (unknown cause)
At 08.10 on the morning of 7 th March 1916 the German battle cruiser Seydlitz sighted a submarine north of Juist Island. The cruiser and her accompanying torpedo boats dropped depth charges but to no avail. A few hours later another German cruiser, the Regensburg sighted a submarine to the east, not far from a German minefield of the Western Ems. E5 failed to return from her patrol and it is believed that this was the submarine seen by the Regensburg near the minefield.
24 March 1916
Possibly mined in North Sea
On the morning of 21 st March 1916 E24 sailed from Harwich for mine-laying operations at Helegoland Bight. The submarine failed to return from this operation and was believed to have struck a mine. In 1973 her hull was mistakenly salvaged, inspection of the hull indicated that the submarine had indeed hit a mine.
25 April 1916
Torpedoed in North Sea by UB18
On the morning of 25 th April 1916 HMS E22 was on surface passage in the North Sea. At just after 1150 a torpedo fired from the German submarine UB18 struck the vessel sending her immediately to the bottom. Of the crew of 33 only two survived having been picked up by UB18 and taken as Prisoners of War.
2 June 1916
Lost in Baltic (unknown cause)
A torpedo attack by HMS E18 on 26th May resulted in the bows of the Destroyer V100 being blown off. Even though severely damaged the destroyer managed to limp back to port. E18 was sighted by a German aircraft off Memel on 28th May, and then by UB30 off Steinort on 1st June 1916. She was probably mined on or about 2nd June 1916 on route to Reval. The sighting was verified by German sources, namely the UB30 log book and the German naval history of war in the Baltic.
3 July 1916
Possibly sunk in Eastern Ems
On 2 nd July 1916 a German Patrol boat reported a trail of oil on the surface just off the Ems that was thought to be emanating from a submarine. The following day German forces attacked a British submarine with both gunfire and bombs. This vessel is believed to be E26 as she failed to return from her patrol.
15 July 1916
Mined in Adriatic
On 15 th July whilst patrolling off the Austrian Naval base of Cattaro, HMS H3 struck a mine and sank.
9 August 1916
Sunk in Venice by aircraft (No loss of life)
Having taken part in the blockade of Pola, HMS B10 retuned to Venice and tied up alongside the Italian Cruiser Marco Polo , which was acting as depot ship. On 9 th August 1916 aircraft of the Austrian Naval Air Service raided the port. B10 was hit and settled on the seabed.
15 August 1916
Sunk of Harwich after collision with HMS E41
Whilst carrying out anti submarine exercises in the North Sea, HMS E41 acting as a target, had begun a surface passage of 12 knots when HMS E4 's periscope appeared 50 yards off her starboard bow, on a collision course. E41 stopped her engines but not before E4 collided forward of the bridge. E41 began to take in water through the forward battery compartment and began to sink by the bow. In less than two minutes the conning tower was under the water. HMS Firdrake , who had been monitoring the exercise, took less than two minutes to reach the scene of the collision to pick up survivors. There were no survivors from E4 . Both submarines were eventually located, salvaged and returned to service.
15 August 1916
Sank off Harwich after collision with HMS E4
Whilst carrying out anti submarine exercises in the North Sea, HMS E41 acting as a target, had begun a surface passage of 12 knots when HMS E4 's periscope appeared 50 yards off her starboard bow, on a collision course. E41 stopped her engines but not before E4 collided forward of the bridge. E41 began to take in water through the forward battery compartment and began to sink by the bow. In less than two minutes the conning tower was under the water. HMS Firdrake , who had been monitoring the exercise, took less than two minutes to reach the scene of the collision to pick up survivors. There were no survivors from E4 . Both submarines were eventually located, salvaged and returned to service
22 August 1916
Lost in North Sea (unknown cause)
E16 was last sighted thirty-five miles east of Yarmouth by HMS E38 . E38 later observed a group of warships moving north, in the vicinity of Terschelling, Splashes were seen near to one of the warships which may have been depth charges exploding. Reports of enemy vessels attacking a periscope on the 22 nd August may have been against E16 .
22 November 1916
Possibly mined off Orford Ness
E30 left Harwich on November 15 th . Sunk in the North Sea, possibly due to a mine off Orford Ness. The minefield was not located until 25 th November.
30 November 1916
Cause unknown
19 October 1917
Lost in North Sea possibly after collision with HMS E43
E36 and E43 left Harwich at 0730 on 19 th January 1917 for two patrol areas off Terschelling. A strong north easterly was blowing. At 1126 just before they left the coast, E43 signalled to E36 to proceed independently. At 1330 E36 was on the port beam but was out of sight by 1500. The sea was running fairly high and at 1850 E43 , having lost her bridge screen, eased to 5 knots and turned 16 points to fit a new one. This delay must have enabled E36 to overtake her, for at 1950 off the Haaks LV, E43 had just altered course to true north when she suddenly sighted a submarine 3 points on the port bow apparently steering east and only 50 yards off. The helm was put hard to starboard and engines full astern but E43 struck E36 aft from the stern, rode right over her and saw her vanish on the starboard quarter in the darkness. E43 went astern but nothing could be seen in the darkness and heavy sea. Nothing more was heard of E36 .
29 January 1917
Sank in Gareloch during trials
Just after noon on 29 th January 1917, HMS K13 , on trials in the Gareloch, signalled to nearby HMS E50 her intention to dive. As the submarine submerged the engine room began to flood. The submarine became uncontrollable and came to rest on the bottom with the engine room and after torpedo room flooded.
The crew of E50 witnessing K13 's rapid dive closed in on the area discovering traces of oil and escaping air breaking the surface. The first rescue vessel arrived around midnight. Divers were sent down to inspect the submarine and just after daybreak on the 30 th morse signals were exchanged between the divers and the trapped crew. At 1700 an airline was successfully connected, empty air bottles recharged and ballast tanks blown. With the aid of a hawser slung under her bows K13 was brought to within 8 feet of the surface. By midday of the 31 st K13 's bow had been raised ten feet above the water. By 2100 the pressure hull had been breached using oxy-acetylene cutting equipment the survivors being transferred to safety. K13 was finally raised on 15 th March, refitted and returned to service as HMS K22.
12 March 1917
Mined off Huney Island, Shetlands
On leaving Balta Sound for patrol, E49 hit a mine laid by UC76 on the 10 th , off the entrance. There were no survivors. She lies in 16 fathoms with bows blown off.
17 March 1917
Sank off Androssan after ballast tank flooding
May 1916: Paid off and placed in reserve.
A10 foundered while moored alongside HMS Pactolus , at Eglinton Dock, Ardrossan. She was re-floated and sold two years later.
16 April 1917
Sank off Harwich after collision with HMS Melampus
On exercises off Harwich, at periscope depth, C16 collided with the destroyer HMS Melampus , sustained damage and bottomed in 60 feet. In an effort to raise the alarm on the surface an attempt was made by the First Lieutenant to escape the submarine via a torpedo tube but he was drowned in the attempt. The crew next tried to flood the entire boat and escape through the fore hatch but a fender jammed in the hatch. Before this last attempt the Captain made out a report which was later found in a bottle near his body by the salvage team.
17 July 1917
Torpedoed East of Fair Isle by U52
Sunk, by German U-boat U52 off the Shetlands. She was on the surface.
20 August 1917
Lost in North Sea (unknown cause)
Failed to return from a North Sea patrol.
16 September 1917
Rammed in error by HMS Pasley
G9 left the Tees on 9 th September 1917. On the 16 th she was on patrol between 60 degrees 30 minutes north and 61 degrees 30 minutes north. It was a very dark night and G9 knew an enemy submarine was in the vicinity. There was heavy rain, with sea state 5 and wind force 4-5.
Whilst on the surface, G9 fired a torpedo at the destroyer HMS Pasley in mistake for German U-boat. The torpedo failed to explode and the destroyer rammed the submarine. The CO of Pasley had received no instructions regarding probable presence of British submarines in this area. The subsequent Court of Enquiry attributed no blame to Pasley.
22 October 1917
Grounded off Vaist Bay - Blown up to avoid capture
Based at Rogekul to operate in the Gulf of Riga, the submarine was seriously damaged during attack on German naval forces in October 1917. Deliberately ran aground and destroyed by her crew near Pernau, Gulf of Riga, on 22 nd October 1917.
18 November 1917
Damaged off Danish Coast after collision with HMS K4
Sunk to avoid capture
The Light-cruiser HMS Blonde was heading K1 , K3 , K4 and K7 in line ahead off the Danish coast when she was forced to turn sharply to port to avoid three cruisers, that crossed her bows from starboard to port.
The abrupt change of course took the submarines by surprise and K1 and K4 collided. K1 had lost way due to salt-water, instead of fuel, coming through the sprayers and extinguishing the boilers. K3 passed close on the port side. K4 , following K3 , suddenly observed the red light of K1 , and, although taking avoiding action, struck K1 a glancing blow abreast the conning tower. Water poured into the control room. Within minutes, chlorine gas was being released from the batteries. Blonde was signalled that K1 was sinking, and the cruiser closed, lowering two cutters. The rescue boats made five trips and transferred all 56 members of the crew to Blonde . A discussion was then held as to whether K1 could be saved, and it was decided to sink her.
14 January 1918
Lost in North Sea (unknown cause)
In January 1918 G8 left for a patrol in the North Sea. She failed to return and it is believed she fell victim to a mine on or around 14 th January.
19 January 1918
Lost in North Sea (unknown cause)
H10 sailed from Harwich to patrol in the North Sea in January 1918. She did not return and it is believed that she struck a mine on 20 th January.
28 January 1918
Sunk by shore based guns in Dardanelles
On 20 th January 1918 the German Destroyer Goeben had sunk two English vessels off the Dardanelles. The Goeben had been damaged by mines but managed to withdraw up the Dardanelles until she ran aground off Nagara Point. It was decided to make a concerted effort to sink her; over five days 270 aircraft sorties were flown and although 16 hits were scored the Goeben refused to sink.
On 27 th January air reconnaissance reported that the destroyer was still aground and E14 was sent from Muldros to finish off the Goeben. Unfortunately, the Goeben had been moved that very afternoon and E14 had negotiated the treacherous straits for nothing.
On the journey back E14 fired a torpedo at a Turkish ship at 0845 on the morning of the 28 th . Eleven seconds later an enormous explosion shook her; either a torpedo had detonated early or E14 had been depth charged. Whatever the cause, E14 was severely damaged, with water pouring in unchecked. The submarine was forced to surface where it was met with a barrage of gunfire. After half an hour it was clear that the best hope for survival was to beach her. While attempting to beach the submarine, she received a direct hit, E14 was now beyond hope and sank with the loss of 23 of her crew.
31 January 1918
Sank in Forth Estuary after collision with HMS Fearless
Whilst taking part in exercises off May Island, K17 was astern of HMS Courageous when the latter changed course to avoid two trawlers, which were spotted ahead. K17 turned but K22 and K14 were involved in a collision. Meanwhile HMS Fearless was steaming at 21 knots towards the area oblivious of the accident. Suddenly the Fearless appeared over the horizon and ploughed into K17 , water gushed into the boat through the pierced pressure hull. The order to abandon ship was quickly given. Within 8 minutes K17 had disappeared. The survivors were now in the water and the other submarines attempted to pick them up. Sadly the destroyers were unaware of the location of the accident and ploughed through the survivors.
31 January 1918
Sank in Forth Estuary after collision with HMS K6
On 31 st January 1918 HMS K4 left harbour bound for a North Sea exercise. In what became known as the Battle of May Island a number of submarines were lost. Several collisions occurred, including K6 colliding with K4 . So great was the collision that K4 was cut almost in two and sank immediately with the loss of all onboard.
1 February 1918
Possibly mined in the North Sea
HMS E50 is thought to have struck a mine on or around 1 st February 1918 in the North Sea
2 March 1918
Rammed in error in Irish Sea by SS Rutherglen
H5 sailed for patrol in the Irish Sea with instructions to patrol a line extending 10 miles east from Carnarvon Bay Light Ship. At 0830 on 2 nd March the steamer Rutherglen sighted a submarine, which crossed its bows at considerable speed. Believing the submarine to be a U-boat Rutherglen rammed the vessel. Cries were heard in the water and a strong smell of petrol was also present. Nothing more was heard from H5 and it is believed that she was Rutherglen's victim.
12 March 1918
Bombed in error off Fechamp
D3 left Gosport on 7 th March 1918 for an anti-submarine patrol in the English Channel. Little is known of her patrol movements but it is believed that a submarine spotted by a Royal Naval Air Service airship on the 11 th was D3 . On the 12 th March the French airship AT-0 was patrolling when at 1420 a vessel was spotted to her north east. The airship drew close for recognition purposes and according to her commander, the submarine fired rockets at her. Four 52-kilo bombs were dropped by the airship. The submarine disappeared but several minutes later men were seen in the water. Attempts were made by the airship to rescue the men but it proved too difficult. The airship withdrew to seek help but all the men had drowned by the time it arrived. It is clear that D3 was the victim of a serious identification error on the part of the French airship, with identification rockets being mistaken for aggressive gunfire.
3 April 1918
Scuttled in Helingfors Bay, Finland to avoid capture
E1 was paid off at Helsingfors at the end of December 1917, with her crew returning to the UK In January 1918. On the 3 rd April 1918 the vessel was scuttled to avoid capture following the Treaty of Brest Litovsk.
3 April 1918
Scuttled in Helingfors Bay, Finland to avoid capture
Scuttled, on 3 rd April 918, at a point 1.5 miles south of Grohara Light off Helingfors, to avoid capture by the Germans following the Treaty of Brest Litovsk.
3 April 1918
Scuttled in Helingfors Bay, Finland to avoid capture
Scuttled, on 3 rd April 1918, at a point 1.5 miles south of Grohara Light off Helingfors, to avoid capture by the Germans following the Treaty of Brest Litovsk.
4 April 1918
Scuttled in Helingfors Bay, Finland to avoid capture
Scuttled, on 4 th April 918, at a point 1.5 miles south of Grohara Light off Helingfors, to avoid capture by the Germans following the Treaty of Brest Litovsk.
4 April 1918
Scuttled in Helingfors Bay, Finland to avoid capture
Laid up at Helingfors with the remained of the Baltic Flotilla in December 1917. Scuttled on 4 th April 1918 at a point 1.5 miles south of Grohara Light, Helingfors, to avoid capture by the Germans after a Peace Treaty was signed between Russia and Germany. The submarine was subsequently salvaged in August 1953 and broken up in Finland.
5 April 1918
Scuttled in Helingfors Bay, Finland to avoid capture
Scuttled, on 5 th April 1918, at point 1.5 miles south of Grohara Light, Helingfors, to avoid capture by the Germans after a Peace Treaty was signed between Russia and Germany.
5 April 1918
Scuttled in Helingfors Bay, Finland to avoid capture
Scuttled at point 1.5 miles off Grohara Light, Helingfors, to avoid capture by the Germans after the Peace Treaty of Brest-Litovsk was signed between Russia and Germany.
23 April 1918
Explosive ship - Zeebrugge
By 1917 German submarines had wreaked havoc on British shipping, which threatened Britain's very ability to continue to fight. It was decided that the best way to stop the carnage was to block the gateways by which the U-boats entered the North Sea, namely Ostend and Zeebrugge. A plan was devised for an assault on the harbours, a key part of which entailed the partial destruction of the viaduct connecting the Zeebrugge Mole to the mainland to prevent reinforcements being rushed from nearby Bruges. This part of the assault required the use of submarines, which were to be pack ed with explosives, and rammed against the viaduct; the antiquated C1 and C3 were selected for the task.
On 24 th April 1918 the submarines were towed by destroyers to an assembly point where they were to make their own way to the viaduct. C3 rammed the viaduct at 9 knots and stuck fast. The crew took to motorboats, as a 12-minute fuse was set. With the motorboats only 200 yards away the submarine erupted blowing a large hole in the viaduct.
28 June 1918
Sunk off Irish coast by UB73
On 28 th June 1918 whilst on patrol in the North Sea D6 was sunk by UB73 .

Lost In North Sea (unknown cause)
On the morning of 14 th July 1918 HMS E34 left Harwich to lay mines off Vlieland. She was lost with all hands on the 19 th . The exact cause of her loss is unknown.

3 October 1918
Sunk north of Terschelling by gunfire from German ships
On the morning of 3 rd October 1918 HMS L10 was in the vicinity of a German convoy, which had, the previous night, been attacked by British Destroyers. That afternoon a number of German ships were spotted searching the area for survivors and L10 signalled her intention of attacking the German squadron, which consisted of the Destroyers S33 and S34 and two torpedo boats heading from Zeebrugge to Germany.
S34 struck a mine with the result that the other ships were forced to ignore the danger of mines to rescue the sinking destroyer's crew. L10 moved in and fired a torpedo at S33 . S33 was severely damaged but initial thoughts of another mine were dispelled when L10 's conning tower broached the surface. S33 managed to bring her guns to bear and sank the submarine through persistent shelling.
October 1918
Sank off Immingham after collision with HM destroyer
October 1918 following a main motor failure C12 was driven by the tide against a destroyer lying at the Eastern Jetty, Immingham and was holed and sank.

15 October 1918 Sunk in error off Blyth by Q Ship HMS Cymric
On 15 th October 1918 HMS J6 was lying on the surface outside Blythe. The Q-ship Cymric was also in the area and had already encountered two British submarines that day. At 1600 a third submarine was spotted closing to have what the Cymric thought was a good look before attacking. The Cymric at once went to action stations believing the submarine to be the German U-boat U6 ; As shells poured into the submarine the signalman attempting to hoist a recognition signal was killed. J6 attempted to lose the Q-ship by entering a fog bank Cymric followed and found the submarine settling in the water. It was only when survivors were picked up that the mistake became clear.

1 November 1918
Lost in North Sea (unknown cause)
In October 1918 G7 set sail for a patrol in the North Sea. Communications were lost on the 23 rd and she was declared lost a week later.

22 November 1918
Wrecked off Harwich during Fog
Recalled on 22 nd November from a patrol off Dogger Bank HMS G11 ran ashore, in thick fog, near Harwich and was unable to be saved.

4 June 1919
Possibly sunk near Kronstadt by Soviet Warship
On 4 th June 1919 while patrolling in the Baltic, during the war against the Soviets, L55 was attacked by two Soviet destroyers and sunk by heavy shellfire.
In August 1928 the Soviets announced that L55 had been raised. The Admiralty requested that the remains of her crew be returned. These were collected by a merchant ship before being transferred to HMS Champion . On 7 th September 1928 the crew of L55 were finally laid to rest in a single grave at the Royal Naval Cemetery, Haslar.

18 October 1919
Sank at Blyth when holed by propeller of HMS Vulcan
Sunk alongside at Blyth on 18 th October 1919 after being holed in a collision, by the propeller of HMS Vulcan .

20 January 1921
Sank off Isles of Scilly (unknown cause)
On 20 th January 1921 HMS K5 sailed from Torbay as part of a fleet bound for Spain, which included the Cruiser Inconstant and Submarines K8 , K9 , K15 and K22 . It was decided to conduct a mock battle in the Bay of Biscay and the vessels split up to take their positions. A signal was received from K5 that she was diving, but she failed to reappear at the end of the exercise. An hour before dusk a battery cover from a K boat was recovered and the next morning a sailor's ditty box was found - the last trace of K5 . It is believed an accident caused K5 to exceed her maximum diving depth.

25 June 1921
Sank of Portsmouth
On the 25 th June 1921 K15 was moored alongside the light cruiser HMS Canterbury , in the tidal basin at Portsmouth. Most of the crew were on leave when a watch keeper discovered that the submarine was sinking, with the stern already awash. The watch were quickly roused and scrambled aboard the Canterbury. The submarine slowly submerged amid streams of bubbles. The accident was caused by hydraulic oil expanding in the hot weather and contracting as the temperature dropped causing a loss of hydraulic pressure and causing vents to open.
23 March 1922
Sank off Gibraltar following collision with HMS Versatile
As part of the 3 rd Submarine Flotilla H42 had spent Christmas 1921 in Portsmouth before sailing in January 1922 for exercises in the Mediterranean. H42 surfaced just off Gibraltar 120 yards in front of the destroyer HMS Versatile who at that time was cruising at 20 knots. The Destroyer was unable to take avoiding action and ploughed into the submarine almost slicing her in two.

18 January 1923
Sank in Hong Kong Harbour during a typhoon
HMS L9 broke adrift from a buoy in Hong Kong during a typhoon. The submarine struck a merchant ship and damaged a dockyard wall before foundering.

10 January 1924
Sank off Portland following collision with HMS Resolution
HMS L24 was detailed to take part in Exercise GA in January 1924, which was intended to improve submarine tactics in dealing with aircraft, both friendly and hostile. On 10 th January HMS Resolution , a 29,000-ton battleship, left Portland bound for the exercise. After several hours at sea a lookout on board the Resolution reported a disturbance on the surface ahead and at 1113 a slight bump was felt. L24 was shortly afterwards reported missing and salvage vessels were dispatched to the area.
Unfortunately night soon fell and the weather the next day prevented any further search and by the 12 th all hope of finding survivors had to be given up. The Resolution was checked for evidence of a collision, her chain was found to be fractured at the very bottom and this was taken as evidence of a collision. It is believed that L24 was unaware of the Resolution 's position having carried out a mock attack on another ship and was surfacing when she suddenly became aware of the looming battleship. A crash dive was probably attempted but L24 was unable to avoid the battleship.

12 November 1925
Sank in English Channel following collision.
On 12 th November 1925 M1 sailed from Plymouth to take part in an exercise. Several vessels reported seeing the submarine on the surface during the course of the proceedings and M1 exchanged messages with the minesweeper Newark at 0730. At 1937 M1 dived and never resurfaced.
What happened to the submarine remained a mystery for several days until the Captain of the Swedish collier Vidar made a report of his journey from Cardiff to Stockholm. On entering the English Channel British warships were seen carrying out exercises. The Vidar was continuing on her way when at 0745 a heavy blow rocked her. The Captain put this down to bombs being used in the exercise as his ship was still perfectly watertight, and proceeded on his way without communicating with the warships. Only on reaching the Kiel Canal on 16 th November did he read about the ongoing search for the submarine. Three days later it was possible for divers to inspect the hull of the Vidar where it was found the stem had been bent and several rivets were missing, indicating a collision with an underwater object. Traces of paint on the colliers stem were later found to be identical to that of M1 . The search for M1 continued for a month until on 2 nd December the Admiralty announced that the search was to be discontinued as nothing had been found.

9 August 1926
Sank at Devonport - surface trimming with hatches open
On Monday 9 th August 1926 HMS H29 lay alongside No.2 Basin in Devonport Dockyard. She had recently completed a refit and it was necessary to test the torpedo tube mechanisms. In order to do so the submarine was required to be "trimmed down". As the submarine began to trim several men came rushing on deck. H29 's stern began to sink low in the water and attempts to shut the aft hatch were thwarted by a 4-inch pipe passing through it. Water began to rush through the hatch before the pipe could be removed. H29 sank in under 2 minutes.

9 July 1929
Sank off Pembrokeshire Coast following collision with HMS L12
On Tuesday 9 th July 1929 HMS L12 was at sea with an Officer Training Class; at the same time H47 was on independent exercises in the Irish Sea. At 0800 both submarines were off the Pembrokeshire coast with L12 ahead of H47 . L12 suddenly altered course to starboard. H47 at once went full astern and to collision stations. The two submarines crashed together with L21 's bow penetrating about 2 feet. In only 15 seconds H47 began to sink. L12 also began to take in water but her crew managed to control the flood.
HMS Poseidon
9 June 1931
Sank north of Wei Hai Wei following collision with SS Yuta
On 9 th July 1931 HMS Poseidon was exercising 20 miles north of her home base of Wei Hai Wei when the steamer Yuta was spotted some distance away. Despite excellent visibility the two vessels collided and the submarine sank within two minutes.

26 January 1932
Sank off Portland whilst surfacing
At 9 o'clock on the morning of 26 th January 1932 HMS M2 left Portland to take part in routine exercises. At 1011 she signalled her intention to dive at 1030. This was the last communication with the submarine. The loss of radio communication did not cause any consternation until M2 failed to return to port as expected at 1615. Search vessels were dispatched but there was no sign of the submarine or her crew. No explanation could be found for her loss until the Admiralty received a report from the captain of the coaster Tynesider which reported seeing a submarine diving stern first off Portland. This had caused the Captain some anxiety but he thought he saw the same submarine a short time later. M2 's exact position remained a mystery for a week until the Destroyer Torrid picked up sonar sounds that indicated a sunken submarine; divers confirmed this to be M2 lying with her stern in the sand at a depth of 90ft
Two bodies were recovered from the wreck during the next week. A number of attempts were made to raise the vessel but all failed.

HMS Thetis
1 June 1939
Sank in Liverpool Bay during trials
On 1 st June 1939 HMS Thetis left Birkenhead for Liverpool Bay to conduct her final diving trials, accompanied by the tug Grebecock. As well as her normal compliment of 59 men she was carrying technical observers from Cammel Laird and other naval personnel, a total of 103 men. At 1340 pm Thetis signalled her intention to dive and that she would be submerged for 3 hours. As the submarine began her dive it became clear that there was a trimming problem as she would not submerge, despite the ballast and auxiliary tanks being full and 50 extra men on board. Such problems were not uncommon in new submarines but it was necessary to check that Thetis had taken in sufficient water to submerge. Part of the check entailed examination of the six bow torpedo tubes to ensure that tubes 5 and 6 contained the 100 gallons expected. The Torpedo Officer first checked tubes 1 to 4 and all were dry. On opening the test-cock to tube 5 it appeared the tube was dry. As the tube was opened water cascaded into the submarine.
In the control room ballast tanks were blown, but too much water had entered the submarine and she became wedged in the mud at a depth of 150 feet at an angle of 45 degrees. An Indicator Buoy was released and smoke candle fired. By 1600 Grebecock was becoming concerned for the safety of Thetis and radioed Gosport. A search was immediately instigated. Next morning HMS Brazen found the Thetis with her stern clear of the water, and dropped charges to mark her arrival to any survivors still trapped in the submarine. The survivors began their escape two men appeared on the surface followed by two more. These were the only men to escape from Thetis . Attempts were made to cut holes through the pressure hull. A wire that had been placed around her stern finally parted and the submarine slipped beneath the waves.

HMS Oxley
10 September 1939
Torpedoed in error off Obrestad, Norway by HMS Triton
HM Submarines Oxley and Triton were patrolling off Norway on 10 th September 1939 and had been in regular contact when Triton spotted an unidentified submarine off the coast of Norway. Believing it might be Oxley a number of signals of recognition were flashed by Triton . No reply was forthcoming and after several challenges Triton fired two torpedoes that struck the submarine and sent her to the seabed. Triton closed in on the area and found three survivors. A Board of Enquiry found that Oxley was some way out of position and that Triton had acted correctly and was not culpable for the sinking.
HMS Undine
7 January 1940
Sunk south west of Heligoland by German A/S trawlers
HMS Undine was on her fourth war patrol in January 1940 when her asdic failed due to a leak. At 0940 on 7 th January, Undine sighted what was thought to be three trawlers 20 miles west of Heligoland; but were in fact German minesweepers. Undine unsuccessfully attacked the leading vessel; minutes later there was a large explosion followed by others as the minesweepers opened fire. Undine was at 50 feet and proceeding blind due to the loss of asdic. After 5 minutes of no further attacks Undine raised her periscope as she did so an explosion shook the submarine, blowing her upwards and rendering the hydroplanes useless. Without the use of the hydroplanes escape would have been impossible and the order to abandon ship was give. Whilst the crew entered the water, to be picked up by the minesweepers, demolition charges were set and the submarine scuttled.

HMS Seahorse
7 January 1940
Possibly sunk by German A/S craft
On 26 th December 1939 HMS Seahorse sailed from Rosyth for patrol off the east coast of Denmark. Four days later she shifted position to the entrance of the Elbe. She did not return on her due date of 9 th January 1940. It was first thought that she had been mined but German records, examined after the war, suggest she was the victim of the German First Minesweeper Flotilla which reported a sustained depth charge attack on an unidentified submarine on 7 th January 1940.
HMS Starfish
9 January 1940
Sunk south west of Heligoland by German minesweeper trawlers
HMS Starfish sailed from Blyth for patrol on 5 th January 1940. Nothing of note occurred until the 9 th when the submarine sighted a German destroyer and decided to attack. The submarine dived and made her tubes ready. A communication problem caused the first attack to fail and as the submarine returned to periscope depth to carry out another attack she was rocked by an explosion. Further depth charge attacks forced Starfish to settle on the bottom and wait for the enemy to move on. At 1815 Starfish returned to the surface, all confidential documents were destroyed and the submarine scuttled. The ship's company were picked up by the waiting ships and taken as prisoners of war.
HMS Thistle;
10 April 1940
Torpedoed off Utsira, Norway by U4
In the belief that a German invasion of Norway was imminent Flag Officer Submarines ordered HMS Thistle to Stavanger with orders to sink any enemy vessel that she may spot in the harbour. On 10 th April Thistle signalled her intentions in complying with this order and that she had two torpedoes remaining after an unsuccessful attack on a U-boat. With this in mind the Admiralty changed her orders to patrol off Skudenes. No further contact was made with the Thistle . It was later discovered that U4 , the U-boat Thistle had previously attacked had, sighted the submarine on the surface and sunk her with torpedoes.

HMS Tarpon
10 April 1940
Probably sunk in North Sea by German Q ship
On 5 th April 1940 HMS Tarpon left Portsmouth for Rosyth in company with HMS Severn . The following day they were ordered to Norway. On the 10 th Tarpon was signalled to take up a new position. Unknown to the Admiralty the submarine had already been lost. Post War German records showed that Tarpon attacked the Q-ship Schiff 40 at 0724: the first torpedo missed as did a second. The Q-ship picked up the Tarpon on her sonar and her periscope was sighted, depth charges were dropped. The counter attack went on most of the morning until finally at 1252 a pattern of depth charges brought wreckage to the surface. The Schiff remained on the scene until 0500 the next morning secure in the knowledge that she had sunk the submarine.
HMS Sterlet
18 April 1940
Sunk in Skagerrak by German escort Vessel M75
On 8 th April 1940 HMS Sterlet left for a patrol in the Skagerrak, Norway. Four days later she signalled that she had unsuccessfully attacked a Convoy of 3 Merchant ships and a Destroyer. The following day she was assigned a new patrol area and on the 18 th torpedoed the German Gunnery Ship Brummer , causing serious damage. At once the German escorts counter attacked with repeated depth charge attacks. Their target never resurfaced.
HMS Unity
29 April 1940
Sunk off Tyne following collision with Norwegian Steamer Atle Jarl
At 1730 on 29 th April 1940 HMS Unity sailed from Blyth to support the struggle for Norway. The weather and visibility down to 300 yards as Unity moved out of the harbour; in the main channel, where the Norwegian ship Atle Jarl was proceeding on her way from Scotland to the Tyne visibility was down to 100 yards: Neither vessel was aware of the other until the submarine spotted the ship at 50 yards and on a collision course. There was just time to shut the bulkhead doors and order the engines astern before the Atle Jarl smashed into the submarine. The order to abandon the submarine was given and Unity sank only five minutes after the collision.

HMS Seal
5 May 1940
Captured in Kattegat after striking a mine
On 29 th April 1940 HMS Seal was bound for mine laying operations in the Kattegat. Just before dawn on the 4 th May she was sighted by a German aircraft, which attacked at once. No serious damage was caused but German anti-submarine forces were alerted to her presence and set about finding the submarine. At 1900 a violent explosion shook Seal as her stern struck a mine. Following the explosion the stern of the submarine became stuck in the mud and the submarine refused to budge. When the Seal finally returned to the surface in the early hours of May 5 th , enemy aircraft were waiting and she came under sustained attack and unable to dive there was no other option than to surrender.

HMS Odin
14 June 1940
Sunk in Gulf of Taranto by Italian Destroyer Baleno
The Italian Destroyer Strale sighted HMS Odin at 23.21 on 13 th June. The Destroyer turned to attack, first with torpedoes, and then with gunfire. Strale then attempted to ram the submarine, which fired a torpedo from a stern tube before diving. Having failed to ram the submarine, the Strale launched a pattern of depth charges before returning to her designated patrol. At 0157 the Torpedo Boat Baleno sighted Odin surfacing about 9 miles from the position of the original attack. The Baleno also attempted to ram the submarine, which once again dived to avoid her pursuer. Passing over the area Baleno dropped two depth charges, turned and dropped three more. Later that morning aerial reconnaissance by the Italian Air Force revealed oil slicks in both attack areas. The Italians believed the attacks to be on two separate submarines. But it is believed that both attacks were on Odin . The first badly damaging the submarine, the second finished her off.
HMS Grampus
16 June 1940
Sunk east of Syracuse, Sicily by Italian TB Polluce
On the 10 th June 1940 HMS Grampus sailed from Malta to lay mines off the port of Augusta. Three days later she reported this had been done successfully but nothing further was heard and she did not return from the patrol. It is believed that the Italian Navy sank her on the 16th June. At 1900 on the 16 th the Torpedo Boat Circe spotted a periscope and launched a depth charge attack on the position, along with the Polluce . The ninth depth charge pattern destroyed Grampus , which gave up a mass of wreckage.

HMS Orpheus
19 June 1940
Possibly sunk off Tobruk by a mine
HMS Orpheus was the third submarine to be lost in the space of a week. Although the cause of her loss is not certain, it is believed that it was due to a minefield off Tobruk.

HMS Shark
6 July 1940
Scuttled off Stravanger to prevent capture following aircraft damage
On the 5 th July 1940 HMS Shark was on the surface when a seaplane was sighted astern. As the submarine submerged to avoid the aircraft two or three bombs exploded close to the stern, followed closely by at least two more. The explosions caused considerable damage. With out steering gear and the hydroplanes jammed hard to rise, the submarine's bow broached the surface to be greeted by more bombs. The submarine began to sink by the stern and all high-pressure air was used to return her to the surface. Once on the surface Shark got underway steering on main engines. Being sighted yet again the submarine came under sustained attack and No. 4 ballast tank was holed. Finally more aircraft arrived and Shark had no option but to capitulate. At about 0400 four trawlers arrived to take Shark under tow but the submarine was beyond saving, she began to sink at the stern.

HMS Salmon
9 July 1940
Possibly mined in the North Sea
HMS Salmon sailed from the UK for a patrol off the southwest of Norway on 4 th July 1940. She was ordered to report on 15 th July but failed to do so. Nothing is known off her loss; she is presumed to have struck a mine.

HMS Phoenix
16 July 1940
Probably depth charged off Augusta by Italian TB Albertros
HMS Phoenix left Malta for a patrol of the Sicilian coast in July 1940. Nothing was heard from the submarine after a wireless message transmitted on the night of 14 th /15 th July. It is believed that the submarine struck a mine. Although a submarine, possibly Phoenix , attacked the Italian tanker Dora on 16 th off Santa Croce Sicily, the submarine was counter attacked with depth charges and sunk by the Italian Torpedo boat Albatros .

HMS Narwhal
23 July 1940
Possibly sunk off Norway by aircraft
HMS Narwhal left Blyth on 22 nd July 1940. On the afternoon of 23 rd July she should have passed through (German) grid square 4856, where an aircraft reported attacking a submarine. This was believed to be Porpoise by the Germans but as Narwhal did not report again, it was assumed this attack sank her.

HMS Oswald
1 August 1940
Scuttled after being rammed by Destroyer Ungolino Vivaldi
On 19 th July 1940 HMS Oswald left Alexandria for patrol east of Sicily. At 1230 on the 30 th she spotted a convoy comprising three merchant ships and several destroyers. Oswald's unsuccessful attack on the convoy alerted the Italians to the submarine's presence and the 14 th and 16 th Destroyer Squadrons were ordered to seek out the submarine. On 1 st August the destroyer Vivaldi sighted Oswald on the surface at a range of 2500 metres. The destroyer immediately turned to ram the submarine, striking Oswald 's starboard side. Oswald began taking in water and the order to abandon ship was given. Ninety minutes later a series of explosions shook the submarine and Oswald sank to the bottom.
HMS Spearfish
2 August 1940
Torpedoed in North Sea by U34
HMS Spearfish put to sea from Rosyth on 31 st July 1940 for a patrol off the Norwegian coast. On 1 st August she was spotted on the surface by U34 who attacked and sank her with her last torpedo.

HMS Thames
3 August 1940
Probably mined in North Sea
HMS Thames was on her first war patrol when she went missing. She had sailed from Dundee on 22 nd July to patrol in the North Sea. On the 22 nd July Thames successfully attacked the German torpedo boat Luchs just west of the Skagerrak. The Luchs was acting as part of a screen for the battle cruiser Gneisenau , which is believed to been her original target, and that the Luchs had manoeuvred between the submarine and the battle cruiser just as the former fired her torpedoes. The shortened range and the ensuing explosions may have been the cause of the loss of the Thames although the favoured opinion is that the submarine struck a mine on the night of 2 nd /3 rd August.
HMS Rainbow
10 October 1940
Presumed mined off Libya
In October 1940 HMS Rainbow was on patrol in the Mediterranean, operating in the Gulf of Taranto and later in the Gulf of Otranto. She was due back in Alexandria on 19 th October but failed to return. On 4 th October while attacking a convoy Rainbow collided with the Italian M/V Antonietta Costa and was lost with all hands.
HMS Triad
15 October 1940
Sunk south west of Calabria by gunfire from Italian S/M Enrico Toti
In October 1940 HMS Triad was patrolling the coast of Libya before proceeding to Alexandria. By 20 th October the submarine was overdue. It was initially believed that Italian aircraft had bombed Triad off Calabria, but it was later discovered that she had been attacked and sunk by the Italian submarine Enrico Toti on 15 th .

18 October 1940
Depth charged west of Texel Island by German A/S trawlers
H49 put to sea from Harwich on 17 th October 1940 with orders to patrol off the Dutch coast. At 1510 on the 17 th the submarine sighted a German anti-submarine flotilla of five vessels at a distance of 3000 yards; the flotilla also spotted the submarine. H49 immediately dived to 60 feet and depth charges began to fall around her. The submarine endured over two hours of depth charge attacks until 1850 when a large oil slick was sighted on the surface by the attacking vessels - marking the end of H49 .

HMS Swordfish
7 November 1940
Mined of St. Catherine's Point Isle of Wight
HMS Swordfish sailed from Portsmouth on 7 th November 1940 for a patrol in the North Sea, her specific duty being to relieve HMS Usk . Nothing was heard from the Swordfish after her departure despite efforts on the 15 th and 16 th to have her report her position. It was believed at the time that she had fallen victim to a German destroyer in the vicinity of Brest. This belief remained until 1983 when her wreck was discovered off the Isle of Wight at a depth of 150 feet. It is now clear that the submarine struck a mine shortly after sailing from Portsmouth.

HMS Regulus
26 November 1940
Possibly mined off the Straits of Otranto
On 18 th November 1940 HMS Regulus left Alexandria for a patrol in the Adriatic. Her failure to return on 6 th December signalled her loss with all hands. It is believed that she stuck a mine in the Straits of Taranto, although the Italians claimed to have sunk a submarine on 26 th November; the former explanation is believed more likely.

HMS Triton
6 December 1940
Lost in Southern Adriatic (unknown cause).
HMS Triton left Malta for a patrol in the lower Adriatic and the Straits of Otranto on 28 th November 1940. At 0540 on 6 th December an SOS from the Italian merchant vessel Olimpia was intercepted. Triton immediately set of to intercept her and seems to have made a successful attack before she was her self destroyed in a counter attack by two Italian Torpedo boats. There are also reports that the Italian Torpedo boat Clio may have sunk Triton . This attack is reported to have happened several days after Triton should have left the area and is therefore met with some scepticism
HMS Snapper
11 February 1941
Possibly sunk south west Ushant by German minesweepers
HMS Snapper left the Clyde on 29 th January 1941 for a patrol in the Bay of Biscay. She should have arrived in her patrol area on 1 st February. On the 7 th February she was ordered, by signal, to remain on billet until the 10 th and then to return home with her escort. Snapper failed to make the rendezvous with the escort and was not heard from again. It is believed that she met her fate through a mine or that she was mortally damaged by a minesweeper which attacked a submarine in Snapper's area on the 11 th although Snapper should have been out of the area by then.

26 April 1941
Presumed mined off Cape Bon, Tunisia
On 19 th April 1941 HMS Usk sailed from Malta for a patrol off the north west coast of Sicily. Anti-submarine activity was intense and Usk was accordingly ordered to alter her position until this activity had passed. What happened to Usk during her change of position has never been established, but it is almost certain that she was mined in the vicinity of Cape Bon some time after 25 th April.

HMS Undaunted
12 May 1941
Possibly sunk off Zuara, Libya by Italian TB Pegaso
HMS Undaunted sailed for her Mediterranean patrol from Malta on 1 st May 1941. Ordered to patrol off Tripoli the submarine failed to return on her due date of 11 th May and attempts to contact her failed. It is believed that she fell victim to the Italian torpedo boat Pegaso who had sailed from Tripoli on the 12 th . At 2030 that evening Pegaso signalled that she had attacked a submarine with depth charges and that a large patch of oil had been observed, indication of the submarine's destruction. Against this theory is the fact that by that date Undaunted should have been back in harbour but it is possible that a decision to remain at sea for a day had been taken or that Undaunted may have suffered mechanical problems preventing her return. There is always the every present possibility that the submarine fell foul to a mine.

HMS Umpire
19 July 1941
Sunk off Suffolk following collision with trawler Peter Hendriks
HMS Umpire left Chatham on 19 th July 1941 bound for the Clyde prior to joining the 3 rd Submarine Flotilla at Dunoon. Having stopped over night at Sheerness she joined up with a northbound convoy, although she was not part of the convoy escort. Umpire developed mechanical problems and began to fall behind the convoy which was kept informed of the submarine's progress by radio. At midnight the northbound convoy passed a southbound convoy as expected but Umpire following behind was surprised to see the convoys pass port to port rather than the normal starboard to starboard. Umpire altered her course to port as the first few vessels passed to Umpire's starboard side but the trawler Peter Hendriks remained on a collision course. As the two vessels came together a gash was torn in Umpire's side sending her to the bottom.

HMS Union
20 July 1941
Depth charged south west of Pantelleria by Italian TB Circe
HMS Union sailed from Malta at 1 o'clock on the morning of 14 th July 1941 with orders to intercept a convoy north of Tripoli the following day. She never made the appointed location as she was sunk early that day by an Italian torpedo boat.
HMS Cachalot
30 July 1941
Scuttled off Benghazi to avoid capture
On 9 th July 1941 Cachalot departed from Alexandria loaded with stores bound for Malta and arrived on the 16 th . She left again on the 26 th with personnel bound for Alexandria and instructions to look out for an escorted tanker heading for Benghazi. At 2 o'clock on the morning of 30 th July a destroyer was spotted heading towards Cachalot , forcing the submarine to dive. On returning to the surface the submarine was spotted and attacked by the Italian destroyer which steamed in firing it's guns. Cachalot's diving drill was sorely hampered when the upper hatch jammed, thereby preventing a crash dive, and the Italian destroyer rammed into her, although not at great speed as the Italian Captain had realised that the order to abandon the submarine had already been given. As the crew went into the water the main vents were opened and Cachalot sank in very deep water. All the crew, apart from a Maltese steward, were picked up by the destroyer and transported to Benghazi from where they were taken to a POW camp near Naples, until repatriation in 1943.
18 August 1941
Mined off Tripoli
HMS P32 left Malta for a patrol off Tripoli on 12 th August 1941. On the 18 th P32 sighted a convoy of five merchant vessels heading towards Tripoli. As the submarine returned to periscope depth, to check the convoy's position, she struck a mine on the port side. The submarine took a heavy list to port and began to sink.

20 August 1941
Presumed mined off Tripoli
On 6 th August 1941 HMS P33 sailed from Malta with orders to intercept an Italian convoy bound for Libya. On 18 th August HMS P32 reported hearing a prolonged depth charge attack that lasted for two hours. When the attack was finally over P32 attempted to contact P33 but received no response and it is almost certain that P33 had perished in the attack.
HMS Tetrarch
27 October 1941
Probably mined of Capo Granditola, Sicily
HMS Tetrarch left Malta on 26 th October 1941 bound for Gibraltar. The route she was to take meant her passing through a known minefield. On Monday 27 th she communicated with P34 who was in the same area. This was the last contact with the submarine. It is believed that she struck a mine on 27 th .
HMS Perseus
6 December 1941
Mined off Cephalonia, Greece
On 26 th November 1941 HMS Perseus sailed from Malta to return to Alexandria with instruction to patrol to the east of Greece on her passage. On 3 rd December two torpedoes were fired and it is thought a hit was achieved. Three days later Perseus was off Cephalonia when at 2200 a huge explosion ripped the submarine apart.
20 December 1941
Lost off NW Spain (unknown cause).
In December 1941 news was received of a possible break out from Brest, by the German battleships Scharnhorst, Gneisenau and Prinz Eugen. In expectation of this eight submarines were sent to the area but although the breakout did not take place, H31 failed to return. The submarine had sailed from Falmouth on 19 th December. She was requested to signal her position on the 24 th but did not do so. She is believed to have been mined between these dates in the Bay of Biscay.

HMS Triumph
31 December 1941
Lost in Cyclades (unknown cause).
HMS Triumph left Alexandria on 26 th December 1941 to land a party of commandos ashore and then patrol the Aegean. Four days later she signalled that the party had been successfully landed at Bireans. She was due to return to pick up the commandos on 9 th January but failed to make the rendezvous. Nothing further was heard of the submarine. No axis power claimed her destruction and it is believed that she struck a mine.

HMS Tempest
12 February 1942
Depth charged near Gulf of Taranto by Italian TB Circe
HMS Tempest sailed from Malta on the night of 10 th February to patrol the Gulf of Taranto. On the evening of the 11 th Tempest was signalled that the Italians were aware of a submarine in her vicinity and that it should be assumed that her patrol had been compromised. At 0302 on the 13 th the Italian destroyer Circe sighted the submarine on the surface. Tempest had also seen the destroyer and began to dive. Circe moved in to attack and at 03.32 began depth charging the area. At 0716 Circe , still in contact with the Tempest, began a second attack resulting in oil being seen on the surface. The submarine had been crippled. At 0945 Tempest returned to the surface to be met with gunfire from the Circe . The order was given to abandon the submarine, the crew being pick-up by the destroyer. The Italians attempted to board the abandoned vessel but were held back by rough seas. By 1300 the submarine had settled in the water and the demolition charges set by the Tempest 's crew had failed. With boarding of the submarine impossible due to bad weather, the Italian destroyer opened fire and although more than a dozen direct hits were recorded the submarine refused to sink. Finally the Italians attempted to take the submarine in tow. Two members of the destroyer's crew boarded the submarine and prepared the tow. As Circe manoeuvred to take up the tow Tempest suddenly started to sink forcing those onboard to jump into the sea. HMS Tempest slipped beneath the waves stern first with the bows disappearing vertically.

23 February 1942
Depth charged north of Tripoli by Italian TB Circe
HMS P38 left Malta on 16 th February 1942 to intercept a convoy off Tripoli. By the 23 rd she was in position as the convoy hove into view. Amongst the convoy was the Italian destroyer Circe . At 0800 the Circe reported contact with a submarine and the warships turned to attack. A periscope was sighted but was quickly replaced by bubbles as the submarine dived realising it had been spotted. At 1050 after a flurry of attacks HMS P38 rose stern first out of the water, her propellers turning wildly, before crashing back beneath the waves. A large patch of oil appeared on the surface as well as debris - clear evidence of the submarine's destruction.
26 March 1942
Sunk off Malta by aircraft
On 26 th March 1942 HMS P39 was sitting alongside a jetty in Malta Harbour when German aircraft launched a concerted attack. P39 was serially damaged and while she did not sink, due to the efforts of the crew, it was decided that she was too badly damaged to be worth repairing. She was towed to Kalkara and beached.

1 April 1942 Sunk off Malta by aircraft
On 1 st April 1942 HMS P36 was lying alongside a jetty at Silema Harbour in Malta when the Luftwaffe attacked the harbour. A large bomb landed sufficiently near to the submarine to hole her and she began to sink. Despite desperate efforts to save the submarine she rolled over and sank.

HMS Pandora
1 April 1942
Sunk off Malta by aircraft
HMS Pandora arrived at Malta loaded with stores on 31 st March 1942. Having discharged her oil she was moved to Hamilton Wharf at dawn the following day. A bombing raid began as she was being further unloaded and rather than delay her progress it was decided to continue despite the raid. Between 1500 and 1600 on the afternoon of 1 st April Pandora received two direct hits from bombs and sank.
HMS Upholder
14 April 1942
Probably depth charged north of Tripoli by Italian DE Pegaso
On the 12 th April HMS Upholder was ordered to form a patrol line with HMS Urge and HMS Thrasher to intercept a convoy. It is not known if this signal was received and the submarine failed to return to harbour on her due date. A number of theories exist as to the fate of Upholder , the most likely is that she fell victim to a depth charge attack by the Italian anti-submarine vessel Pagaso on 14 th April east of Tripoli although no debris was seen and the position of the attack would have put Upholder some 100 miles out of position, however, this can be explained by the submarine changing position to find 'richer pickings'. A second theory is that the submarine struck a mine near Tripoli on the night of 11 th April, supported by the fact that a submarine was sighted approaching a minefield.

HMS Urge
29 April 1942
Possibly sunk off Ras el Hilal, Libya by Italian aircraft
On 27 th April 1942 HMS Urge left Malta on passage to Alexandria, where she was due to arrive on the 6 th . The submarine failed to arrive. It is possible that Urge struck a mine outside Malta or that she was sunk by the Italian torpedo boat Pegaso in the eastern Mediterranean.

HMS Olympus
8 May 1942
Mined off Malta
HMS Olympus left Malta on 8 th May 1942 on board were the survivors of HMS Pandora , HMS P35 , HMS P36 and HMS P39 . The submarine struck a mine 6 miles out from St Elmo Light.

HMS P514
21 June 1942
Rammed in error my HMC MS Georgian
On 20 th June 1942 HMS P514 left the Canadian village of Argentia bound for St Johns, Newfoundland. At 0300 on the 21 st the minesweeper Georgian was waiting to provide an escort for a convoy bound for Sydney. The Georgian , unaware that any friendly submarines were in the area, assumed that the dark shape of P514 crossing her bow, was an enemy vessel. The Georgian rammed the mystery submarine amidships and reported it sunk. A rescue mission was immediately sent out but no survivors were found. A Board of Enquiry into the accident accepted that the Captain of the Georgian had acted correctly as there had been no reply from the submarine to his identification challenge.

HMS Thorn
7 August 1942
Probably depth charged off Gevdo Island by Italian DE Pegaso
On the 7 th August 1942 HMS Thorn encountered the Italian torpedo boat Pegaso , escorting the steamer Istria from Benghazi, 30 miles south west of Gaudhos Island, off southern Crete. At 1255 an escorting aircraft was seen to machine-gun the sea's surface and Pegaso moved in to investigate. Just four minutes after the aircraft's attack the Pegaso picked-up a contact and carried out seven attacks after which contact was lost. HMS Thorn failed to return from the patrol and is believed to have been lost in this attack.

HMS Talisman
17 September 1942
Presumed mined south of Sicily
On 10 th September 1942 HMS Talisman left Gibraltar for passage to Malta where she was due no later than the 18 th . Messages were received from the submarine on the 14 th but she failed to arrive at Malta. The Italians claim to have sunk a submarine on the 17 th to the north west of Malta. This is believed to have been the Talisman.

HMS Unique
10 October 1942
Possibly depth charged off northern Spain
HMS Unique left Holy Loch for a patrol in the Bay of Biscay on 7 th October 1942. She left her escort off the Scillies on the 9 th . No more was seen or heard from her after that date. HMS Ursula was in the area on the 10 th and reported hearing underwater explosions that led her to believe Unique was under attack although the Germans made no claims to her sinking.

4 November 1942
Sank on exercise in Loch Striven
X3 sank on the 4 th November due to a leaking engine room induction valve. Attempts made to pump the submarine dry proved fruitless and the 3-man crew made a successful escape.

HMS Unbeaten
11 November 1942
Probably sunk in Bay of Biscay by RAF
While on passage to rendezvous off Bishop Rock, British aircraft made an attack on a submarine in the Bay of Biscay and sank HMS Unbeaten in error.
HMS Utmost
25 November 1942
Possibly depth charged off Marittimo by Italian DE Groppo
HMS Utmost left Malta for a patrol in the Mediterranean in November 1942. On the 23 rd she sank an enemy ship, on the 25 th during her return journey to Malta she was located, attacked and sunk by the Italian patrol vessel Groppo .

HMS Traveller
4 December 1942
Probably mined in Gulf of Taranto
On 28 th November HMS Traveller was carrying out a reconnaissance patrol of the coast of Taranto as part of operation Portcullis (an attack on Italian battleships in Taranto Harbour using chariots) The submarine did not return from the operation and was probably mined on or about 4 th December.

HMS P222
12 December 1942
Probably depth charged off Capri by Italian DE Fortunale
HMS P222 left Gibraltar for a patrol off Naples on 30 th November 1942. Messages were received from her on 7 th December but after that no more was heard. P222 failed to arrive at Algiers on her due date of 21 st December and the Italians claimed to have sunk a submarine by depth charging on 12 th December. This is the most probable cause of the submarine's loss but there has been no confirmation.

25 December 1942
Probably depth charged off Tunisia by Italian DE Ardente
HMS P48 sailed from Malta on the 23 rd December 1942; two days later she was attacked and sunk through depth charging by the Italian torpedo boat Audace north west of Zembra Island in the Gulf of Tunis.

HMS P311
2 January 1943
Presumed mined off northern Sardinia
HMS P311 left home waters to join the 10 th Submarine Flotilla at Malta in November 1942. On the 28 th December the submarine left Malta to take part in Operation Principle - the attack, by chariots on Maddalena Harbour, Sardinia. P311 failed to make the rendezvous; her chariots were never launched and took no part in the attack. Wireless messages were received on 30 th December but no further news was heard. The submarine should have returned to Malta on 8 th January 1943. It is assumed that the submarine struck a mine and sank.
HMS Vandal
24 February 1943
Foundered in Inchmarnock during exercise
On 22 nd February 1943 HMS Vandal cast off from the depot ship HMS Forth to carry out a three-day exercise in the Clyde, which was to include a deep dive on the 24 th . During the exercise the submarine was under no obligation to communicate with her base and no alarm was felt when she did not do so. On 24 th February Vandal was observed leaving her anchorage just north of the Isle of Arran. This was the last seen of her.

HMS Tigris
27 February 1943
Probably depth charged off Capri by German UJ2210
HMS Tigris sailed from Malta on 18 th February for a patrol south of Naples. The submarine was last sighted at 0730 on the 24 th February, 39 miles from Capri. On the morning of the 27 th UJ2210 , escorting a convoy six miles south east of Capri made contact with a submarine and carried out three depth charge attacks, the third attack brought oil to the surface and the contact was noted to be stationary. A forth attack of fifteen depth charges brought a huge bubble of air to the surface. On 6 th March Tigris was ordered to Algiers but there was no reply to this signal and Tigris failed to return to harbour.

HMS Thunderbolt
14 March 1943
Depth charged off Sicily by Italian CVT Cicogna
At 2210 on Friday 12 th March the Italian merchant ship Esterel was torpedoed two miles north of Capo San Vito. Following the attack the torpedo boat Libra was ordered to seek out the submarine responsible - HMS Thunderbolt . The Libra made contact with the Thunderbolt that night and carried out seven depth charge attacks with no result. On Sunday 14 th March the Italian corvette Cicogna obtained a contact and shortly after 0734 a periscope was sighted 2000 yards off the corvette's bow. At 0845 the periscope was again sighted, this time less than 10 feet away. Depth charges were launched at once and the corvette increased it speed and turned for another attack when an explosion lifted the submarine's stern out of the sea at an angle of 90 degrees. The submarine sank through a discharge of air and oil. A further two depth charges were dropped resulting in air bubbles, oil and smoke appearing on the surface were the submarine had sunk. The Cicogna remained on station for an hour but no further contact was made.

HMS Turbulent
14 March 1943
Possibly mined off Corsica or Sardinia
On 23 rd February 1943 HMS Turbulent sailed from Algiers for a patrol in the Tyrrhenian Sea. On 1 st March she attacked and sank the Italian steam ship Vincenz . On the 11 th she is known to have attacked the mail ship Mafalda . The following morning the anti-submarine trawler Teti II sighted the periscope and conning tower of a submarine and attacked, it is believed, without success. Turbulent did not respond to any further messages and did not return when expected on 23 rd March. It is thought that Turbulent fell victim to a mine off Maddalena, Sardinia and the discovery of her wreck in this area has given credence to this theory.

HMS Regent
18 April 1943
Mined in Adriatic
On 12 th April 1943 HMS Regent left Malta for a patrol along the south coast of Italy. Sightings of a submarine on 13 th , 15 th and 16 th off Calabria are thought to be that of Regent At 1545 on the 18 th Regent fired a torpedo at the merchant ship Balcic but missed. This attack took place five miles north of Monopoli. That evening a large explosion was heard in the same area, which is believed to have been the Regent striking a mine.

HMS P615
18 April 1943
Torpedoed off Liberia by U123
HMS P614 left Freetown on 17 th April bound for Takoradi under escort from the minesweeper MM107 . During the night submarine and escort lost contact and on the morning of the 18 th the minesweeper sighted, what was thought to be a torpedo track, pass from port to starboard. Contact was gained with P615 and as there was no evidence of a U-boat in the area the torpedo track was put down to a porpoise. P615 and MM107 regained visual contact and the minesweeper took station 300 yards off the submarine's starboard quarter. At 0950 the minesweeper sighted the merchant vessel Empire Bruce and whilst signalling the ship, noticed that P615 was also signalling, a few minutes later the submarine was seen to explode and sink. Observers suggest that the submarine had been hit on her starboard side by a torpedo although no torpedo track had been seen.
HMS Splendid
21 April 1943
Depth charged off Capri by German destroyer Hermes
HMS Splendid left Malta on 17 th April 1943 with orders to patrol off Naples and later off the west coast of Corsica. On 21 st April the submarine was detected by the German destroyer Hermes, whose depth charge attack forced the submarine to the surface. HMS Splendid was then scuttled by her crew to avoid capture.

HMS Sahib
24 April 1943
Depth charged off Sicily by Italian CVT Euterpe
On 16 th April 1943 HMS Sahib attacked and sank the merchant ship Galiolo , two miles off Capa Milazzo. After firing, the Sahib almost broke the surface. This was noticed by an aircraft, which dropped a bomb but to no effect. The torpedo boat Climene almost immediately obtained contact with the submarine. At about 0545, Sahib came under heavy depth charge attack resulting in the pressure hull being holed at the aft ends. With no way of repairing the damage, the order to prepare to abandon ship was given. The submarine surfaced to be welcomed by a machine gun attack from the waiting aircraft. As the crew left the submarine, Sahib was scuttled.

HMS Untamed
30 May 1943
Foundered off Sandra Island during exercise
On 30 th May 1943 HMS Untamed was exercising with ships of the 8 th Escort Group off Cambeltown. At 0950 that morning Untamed dived and commenced the first run of the day. After three hours the submarine surfaced and prepared for the next run. Just after 1345 the submarine once again dived and the second exercise of the day began. This exercise involved the anti-submarine training yacht Shemara firing practice mortars against the submarine. The first two runs were successful with Untamed indicating her position after each with a white smoke candle. At 1450 following the third run the submarine did not immediately indicate her position, The Shemara fired "INDICATE POSITION" charge, came to a stop and began tapping on the hull. The efforts of the Shemara were greeted by a yellow smoke candle. Shemara moved to a position by the marker and once again began tapping the hull. At this point a swirl of water was seen near the marker. Shemara called a halt to the exercise and signalled the submarine to surface: there was no reply. A second surface signal was sent, again without result. At 1602 Shemara sent a signal for assistance to the Naval Officer in Command and continued to search for the submarine. At 1716 the sound of the submarine blowing her tanks was heard. Using asdic the Shemara located the submarine. For the next ten minutes the sound of the submarine blowing her tanks and stopping and starting her engines could be heard. At 1733 HMS Thrasher arrived to render assistance and tried to contact the Untamed . At 1745 all sound from the submarine ceased. Because of worsening weather conditions divers were not able to inspect the stricken submarine until 1115 on 1 st June - 45 hours after she had dived. There was no reply to the divers tapping on the hull of the submarine and an inspection of the vessels hull showed no obvious damage. Only when the Untamed had been salvaged did the cause of her loss become clear; the forward part of the submarine had been flooded through a sluice valve.

HMS Parthian
7 August 1943
Possibly mined in Adriatic
In July HMS Parthian sailed from Malta for a patrol in the southern Adriatic. On the 26 th she was ordered to patrol off Capo Otranto. This order was cancelled on the 28 th when a new patrol area was given. The submarine was signalled on 6 th August to leave the patrol. This signal was not acknowledged and not further contact was made with the submarine. Parthian was due to arrive at Beirut on 11 th August, her failure to do so was probably caused by a mine on or around 6 th August.
HMS Saracen
14 August 1943
Depth charged off Corsica by Italian CVT Minerva
On 7 th August 1943 whilst on patrol of Bastia, HMS Saracen was spotted by the Italian corvettes Minerva and Eutepe who attacked with an accurate pattern of depth charges forcing the submarine to the surface. As the crew abandoned ship the submarine was scuttled to avoid capture.

16 September 1943
Lost on passage to Norway to attack Scharnhorst
On 11 th September 1943 X9 left Loch Cairnbawn under tow from HMS Syrtis to take part in the attack on the Scharnhorst. During the passage the Syrtis remained on the surface, whilst the x-craft, manned by a passage crew, remained dived. The midget submarine was due to surface at regular intervals to ventilate. On the 16 th Syrtis made the signal for the x-craft to surface. There was no reply. At this point the tow was hauled in and was found to have parted and despite an extensive search, no sign of X9 was ever found.

18 September 1943
Scuttled en-route to Norway to attack Lutzow

22 September 1943
Presumed sunk by gunfire during attack on Tirpitz
X5 was sighted by X7 after the X-craft had crossed a mined area just before the attack on the Tirpitz . This was the last definite sighting of X5 .
In Kaa Fjord X5 allegedly surfaced and was sunk by Tirpitz 's automatics, 500 metres away from her target. Later research has suggested that this was in fact X7 abandoned and circling out of control after her attack, and that X5 never reached her intended destination.
The part played by X5 in the attack is not known but, some time after the attack, divers found wreckage possibly (but not definitely) of X5 about a mile to seaward of the Tirpitz , halfway between her and the entrance to Kaa Fjord.
No bodies or personal gear were found, and of survivors there was no trace. It is believed that she was destroyed by depth-charges; whether she was on her way out at the time, after laying her charges, or whether she was waiting to go in during the next attacking period will very possibly never be known.

22 September 1943 Scuttled after attack on Tirpitz
On 21 st September 1943 X6 's periscope flooded shortly after starting out for the attack on the Tirpitz . With visibility greatly reduced the submarine surfaced behind a coaster and followed it through the anti-submarine nets. After entering Kaa Fjord X6 went down to 60 feet and proceeded blindly, while trying to repair the periscope and the motor brakes which had recently burnt out. By 0705 X6 was within striking distance of her target. During the final approaches the submarine hit a submerged rock forcing it to the surface. X6 was clearly seen by Tirpitz and was attacked with hand grenades, and depth charges. X6 immediately dived and in the process completely flooded the periscope.
Proceeding blind, X6 's first charge was dropped somewhere near the battleship's bridge area but whilst positioning to release the second charge, the submarine struck the battleship. With their position given away the crew had no choice but to release the second charge and scuttle X6 with the submarine sinking towards the forward end of the battleship.

22 September 1943
Sank after attack on Tirpitz
Having penetrated the anti-submarine nets at the entrance to Kaa Fjord, X7 manoeuvred to pass under the nearby anti-torpedo nets and placed explosive charges under the Tirpitz 's funnel and after-turret.
On the return journey X7 was hampered by the anti-torpedo nets and had only travelled 400-500 yards from the battleship when the charges exploded. The resulting shock waves severely damaged X7 and rather than compromising the operation by surfacing, the submarine lay on the bottom for over an hour. With the submarine completely out of action, it returned to the surface to face fierce gunfire. The submarine was unable to hold the surface and sank back to the bottom.

3 October 1943
Scuttled in North Sea after failed attack on Scharnhorst
On 12 th September X10 departed Loch Cairnbawn under tow from HMS Sceptre to take part in the attack on the Scharnhorst . At the appointed time the operational crew took over from the passage crew and proceeded to where the Scharnhorst lay at anchor. A fire in the periscope motor prevented the X-craft from pressing home the attack and she had to withdraw and was taken undertow by HMS Stubborn on 28 th September. On 3 rd October the tow parted and only with great difficulty was the submarine brought back under control. That evening Stubborn received a gale warning and the order to scuttle X10 at the captain's discretion. This was duly done and Stubborn returned to Lerwick.

HMS Usurper
3 October 1943
Possibly depth charged in Gulf of Genoa by UJ2208
HMS Usurper left Algiers on 24 th September 1943 with instruction to patrol of La Spezia. On 3 rd October she was ordered to move to the Gulf of Genoa. No further contact was made and she failed to return to Algiers on the 12 th as expected. The German anti-submarine vessel UJ2208 reported attacking a submarine in the Gulf of Genoa on 3 rd October and it is believed that this may have been the Usurper .

HMS Trooper
10 October 1943
Probably mined east of Leros Isalnd, Aegean
HMS Trooper sailed from Beirut on 26 th September 1943 for a patrol west of the Dodecanese and later to the east of Leros. No signals were received and she failed to return on the appointed date, 17 th October. Mining is strongly suspected.
HMS Simoom
19 November 1943
Possibly mined in Northern Aegean
HMS Simoom sailed for a patrol in the Aegean on 2 nd November 1943. On the 5 th she received a signal to divert to the entrance of the Dardanelles. Ten days later she was sent orders to return to port. The submarine never arrived. On 15 th November German radio broadcasts stated that a submarine had been destroyed in the Aegean and that several of the crew had been rescued. It is unlikely that this was Simoom, as it would have put her miles out of position. None of the claimed survivors stated that they were from Simoom . It is more likely that the submarine struck a mine or was lost through an accident.

7 February 1944
Sunk in Pentland Firth following collision with HMS Syrtis
On 7 th February 1944 X22 was involved in towing exercises with HMS Syrtis when heavy seas and gale force winds washed Syrtis 's Officer of the Watch overboard. The towing submarine immediately turned to rescue the officer and in doing so collided with X22 . The small X-craft sank almost immediately.

HMS Stonehenge
16 March 1944
Possibly mined north of Sumatra
On 25 th February 1944 HMS Stonehenge left Trincomalee to patrol in the northern part of the Malacca Straits. Nothing further was heard from the submarine and she failed to reach Ceylon on 20 th March as expected. It is believed that Stonehenge struck a mine, causing her demise although an accident cannot be discounted.
HMS Syrtis
28 March 1944
Probably mined off Bodo, Norway
HMS Syrtis left Lerwick on 16 th March 1944 for a patrol off the Norwegian coast. On 20 th March she was ordered to an area near Bodo, some 70 miles inside the Arctic Circle. Two days later she sank the steamer Narvik with gunfire. On the 28 th a signal was sent to Syrtis ordering her to return to Lerwick. This signal was never acknowledged and the submarine failed to return. German reports indicate the sinking of a submarine in the Bodo area at the time by shore batteries, but the most likely cause of her loss is a mine.

HMS Sickle
16 June 1944
Probably mined in southern Aegean
HMS Sickle left for a patrol in the northern Aegean on 31 st May 1944. On the 4 th June she fired upon shipping in Mitylene Harbour and was engaged in a gun action with two German patrol vessels during which one member of the crew was washed overboard and taken prisoner. Sickle escaped the engagement and continued on her patrol. On 12 th June the submarine signalled that she had spotted a convoy in the approach to Steno Pass. The convoy suspected the presence of a submarine and dropped two depth charges and, although it seems unlikely that this attack accounted for the loss of the submarine, no further contact was made with her. The most likely explanation for her loss is that she struck a mine in the Kythera Channel on 16 th June.
HMS Stratagem
22 November 1944
Depth charged off Malacca by Japanese destroyer
HMS Stratagem sailed from Trincomalee on 10 th November 1944 with orders to patrol in the vicinity of Malacca where it was believed the Japanese were loading ships with bauxite ore. On the afternoon of the 18 th Stratagem attacked and sank the tanker Nichinan Maru . On 22 nd November a Japanese aircraft spotted the submarine and directed a destroyer to where it had dived. Just after midday the destroyer attacked, the first depth charge causing the submarine's bow to strike the bottom. The submarine was plunged into darkness and the forward part began to flood. Attempts to shut the watertight door to the forward compartment failed and the crew were forced to make their escape.
HMS Porpoise
19 January 1945
Possibly sunk off Penang by Japanese A/S aircraft
On 2 nd January 1945 HMS Porpoise left Trincomalee to lay mines in the vicinity of Penang. The signal received from the submarine confirming that this had been successfully carried out was the last contact made. Japanese records show that a submarine was spotted and bombed by aircraft in the vicinity of Penang. Although not destroyed in this attack, the submarine was wounded and leaking oil that left a trail for the Japanese anti-submarine forces to follow as they closed in for the kill.

6 March 1945
Sank after collision in Loch Striven
On the morning of 6 th March XE11 was exercising in Loch Striven when she collided with a boom defence vessel that was laying buoys.

HMS Truculent
12 January 1950
Sank in Thames Estuary following collision with Swedish tanker Divina
On 12 th January 1950 HMS Truculent sailed from Chatham to carry out trials, having just completed a refit; in addition to her normal compliment she was carrying an additional 18 dockyard workers. The trials complete she set a course for Sheerness, which would take her through the Thames Estuary hat night. At 7 o'clock a ship showing three lights appeared ahead in the channel. It was decided that the ship must be stationary and as Truculent could not pass to the starboard side without running aground, the order was given to turn to port. At once the situation became clear as the cargo ship Divina came out of the darkness: the extra light indicated that she was carrying explosives. A collision was unavoidable. The two vessels remained locked together for a few seconds before the submarine sank.
HMS Affray;
16 April 1951
Foundered north west of Alderney
On Monday 16 th April 1951 HMS Affray left Portsmouth to take part in Exercise Training Spring with a training class of young officers aboard, her orders being to make a daily report between 9 and 10 o'clock each morning and to land a party of Royal Marines on any suitable beach in the patrol area during the night. On the morning of the 17 th Affray failed to report her position as required and rescue vessels were immediately put on alert as repeated attempts to call up the submarine failed. It was known that she had intended to dive 30 miles south of the Isle of Wight, so the search was concentrated off the island but the exact position of Affray was unknown. A number of vessels involved in the search reported faint Asdic signals and the submarine Ambush decoded a message stating, "WE ARE TRAPPED ON THE BOTTOM" but the Affray still could not be found. On the evening of the 19 th the Admiralty regretfully called off the search. While the search for survivors was now fruitless the search for the Affray was to continue. In the middle of June, after nine weeks of searching, an underwater camera focused on the submarine's nameplate. Her final position proved to be 37 miles from her known diving position. She was lying on an even keel on the edge of a series of underwater chasms known as Hurd's Deep in the English Channel. Divers could find no evidence of collision damage but noted that her radar aerial and periscope were raised, indicating that she must have been submerged when she foundered. Both hydroplanes were in the rise position indicating that attempts to raise the submarine must have been in operation before being finally defeated by the incoming water. A reason for the disaster was however soon found when the snort mast was examined. A clean break was discovered 3 feet above the deck leading to the conclusion that metal fatigue had caused the loss, allowing water into the boat through a 10-inch hole. This was confirmed by tests carried out on the recovered mast at Portsmouth, all assertions as to a collision being quashed. Exactly what caused the snorkel to shear at the time it did will in all likelihood never be known.
HMS Sidon
16 June 1955
Sank in Portland Harbour after torpedo explosion in tube
On 16 th June 1955 Sidon was moored beside her parent ship, HMS Maidstone, waiting her allotted time to cast away for torpedo firing trials. At 0825 a loud explosion shook the submarine as one of the highly volatile hydrogen peroxide motors of the torpedoes exploded. A cloud of smoke rose from the conning tower hatch as the order to abandon ship was given. Sidon soon began to sink and at 0845 went down by the bows. Several divers at once entered the water and began tapping messages on Sidon 's hull to those trapped inside the submarine. By early afternoon it was apparent that all 12 men inside were dead or incapable of replying to the tapping. On 23 rd /24 th June Sidon was raised and the deceased were buried on the 28 th in a small naval cemetery in Portland. On 14 th June 1957 Sidon was towed from Portland and sunk as a target. She now lies off Portland at a depth of 34 meters.
HMS Artemis
1 July 1971
Sank in Portsmouth Harbour.
HMS Artemis sank alongside HMS Dolphin in 1971 owing to water entering through the after torpedo hatch which could not be shut because electrical shore supply cables had been passed through it. Three men were trapped onboard the submarine but managed to escape successfully through the Forward escape tower. A bad trim and poor precautions lead to the loss and many lessons were learnt. HMS Artemis never returned to service.