HMS Acheron hit a mine in 1940.

This A-class 1350-ton destroyer was sunk while carrying out high-speed trials south of the Isle of Wight on 17 December, 1940, following repairs to German air-raid damage. She was turning east when she hit a mine and was blown in two.
Her captain, Lt RJ Wilson, other officers and 145 ratings were lost from a full complement of 190, plus 25 dockyard men. Built in 1929, Acheron was 323ft long, beam 32ft, armed with four 4.7in and two 2-pounder AA guns, and eight 21in torpedo tubes.
Both parts of the ship were found by divers in 1984 a quarter of a mile apart on a soft-sand seabed at 48m at 50 30.46N; 01 32.60W. Much of the wreckage is now buried in sand.

This former 1085-ton Lease-Lend US destroyer was hit by a homing torpedo from U764, commanded by Oberleutnant Hanskurt von Bremen on 15 June, 1944 off Portland Bill. Her bows were blown off. She was taken in tow but sank the following dawn 23 miles south-east of Portland Harbour at 50 12.492N; 02 14.467W. Fifty-eight crew were lost.
Divers found the central part of Blackwoods 289ft hull intact and complete with upper deck. A large debris area at the stern is where its depth charges exploded. Diesel-electric engines protrude from the hull. Depth: 56m.

This 1360-ton B-class destroyer of 1931 was escorting a convoy across Lyme Bay on 13 June, 1944, when she received a direct hit from a torpedo dropped from a German aircraft. It detonated the forward magazine, blowing Boadicea nearly in two. She sank at once, taking more than 150 crew with her. Fewer than a dozen were saved.
The main part of the wreck is 6m proud of the sandy 52m seabed at 50 25.70N; 02 45.90W. The bow section has yet to be discovered and the ship ends at the forward part of the engine-room. There is a 4.7 gun at the stern and other AA guns still point skywards. The bell has been recovered.

This US Lease-Lend ship of 1943 served in the RN as a frigate of 1300 tons, 306ft, armed with three 3in guns, ten 20mm AA and one 2-pounder AA.
On 6 December, 1944, she was hit amidships by a homing torpedo seven miles north-east of Cape Wrath, north-west Scotland, by Oberleutnant Erich Taschenmachers U775, and broke in half. The stern part sank two hours later, allowing 97 of the 200 men aboard to be rescued by HMS Hesperus.
Today the very broken wreckage lies scattered in a general depth of 100m at 58 41.975N; 04 12.085W.

Built in 1940, this 904-ton Hunt-class destroyer was 272ft long, with four 4in guns, a 4.2-pounder and eight 20mm AA guns. Under Lt-Cdr RT Lampard she was escorting a convoy off Lowestoft on the night of 25 February, 1941, when attacked by a German E-boat flotilla.
Exmoor fought hard until a torpedo from S30 set off a violent explosion and she sank almost immediately, with the loss of her four officers and 100 ratings. No ships of the convoy were damaged.
The wreck lies in 33m at 52 30.269N; 02 04.997E, intact but for a small section 100ft south of the main wreckage. There is a heavy list to port near the stern. The 4in guns are still mounted at bow and stern. Two propshafts are clear of the seabed and both props have been salvaged.

HMSM K4 & K17
Both these 338ft K-class submarines were lost on 31 January, 1918. The Ks were said by sailors to be under a hoodoo, with a dismal record of accidents. But the worst night was during the Battle of May Island, an exercise that involved a large force of RN warships leaving the Firth of Forth behind two flotillas of K-class submarines. A jammed helm on one of the subs caused two to collide.
Flotilla leader the cruiser HMS Fearless turned back through her flotilla, ramming and sinking K17. Then the second flotilla arrived and in the muddle K6 rammed and sank K4. There were no survivors from either submarine.
K4 lies upright in 48m at 56 15.467N; 02 11.583W, with a deep rent across the hull aft of the rear gun-mount. The conning tower has been forced to starboard, but is still attached at 90.
K17 is not far away at 56 15.430N; 02 11.556W, upright, with propellers clear of the seabed in 58m. The aft gun is in place, the casing vents open, and the hull has been sliced off forward of the conning tower position. The bow lies on the port side and is complete right aft to the officers quarters.

Three M-class submarines were built during WW1 using the hulls of boats of the failed K-class The final design of M1 had four torpedo tubes, a 3in foldaway gun and a massive 12in gun from an old battleship. She could surface, fire the gun and submerge in 40sec. But making the seals around the 60-ton gun watertight in the mounting just ahead of the conning tower took so long that the war was over before she went into service.
She disappeared during exercises on 12 November, 1925. The captain of Vidar, a Swedish collier, later reported an underwater explosion near Start Point at the time of the disappearance, but it was only when she went into dry dock that it became clear that the Vidar had caused the loss of M1.
M1 was not seen again until 1999, when diver Innes McCartney found the wreck off Start Point in 71m, largely intact with a slight list to port. Still in place were the massive gun-turret turntable, smaller foldaway gun and hatches - only the 12in gun and turret were missing, though the breech assembly and much of the turret-plating lay off the port side. The remains of all 69 crew are believed to be still inside, though one hatch aft and one forward of the conning tower are open. M1s position is 49 59.188N;03 56.821W, and depth to the highest point is 62.5m.

This 296ft submarine was built in 1918 and was similar to M1, but the big gun was replaced in 1927 by a small folding-wing seaplane and hangar forward of the conning tower. M2 sank on 26 January, 1932 with the loss of all aboard after an attempted high-speed aircraft launch. The hangar door seems to have been opened before she had fully surfaced.
A massive operation to lift her began when she was found eight days later but was called off a year later.
Today the much-dived M2 is upright on a sandy seabed at 30m at 50 34.60N; 02 33.93W. The hatches are now sealed, but the hangar doors are still wide open.

The first S-class submarine was launched at Chatham Dockyard on
1 December, 1930. The 640-ton, 202ft boat carried a 3in gun, a 0.303 Lewis gun and six 21in torpedo tubes.
She left Portsmouth on 7 November, 1940 for the French coast near Ushant to relieve the submarine Usk but disappeared on route, believed sunk by a German destroyer.
Swordfish was found cut in half by a mine in 36m by Isle of Wight diver Martin Woodward in 1983, south of St Catherines Point. She is broken forward of the gun-mounting, with the forward section on the port side.
The aft section is upright. The forward planes are set to dive, the bridge telegraph still at Slow ahead. The aft escape hatch is open. None of the 40 crew survived. The position is 50 28. 783N; 01 21. 950W.

This 540-ton submarine was rammed and sunk by the trawler Peter H Kendricks in the North Sea off the Wash on 19 July, 1941.
She was 193 ft long with a beam of 16ft. All her crew were lost. Umpire lies to starboard in 15m at 53.09.90N; 01 06.05E. Deck and hull have collapsed and the bow is shattered.

Just three months after launch this 740-ton U-class submarine disappeared during sea trials on 24 February, 1943, in Inchmarnock Water, Firth of Clyde. All 37 crew were lost.
The wreck was found by ROV video cameras in 1994 in 100m at 55 43.683N; 05 20.017W. A technical diving team visited the wreck for the MoD prior to designation and found the name Vandal in brass letters on the conning tower. It is in dark water on a muddy slope, listing 35 to port.
The forward hatch was open, so some of the crew may have tried to escape. The raising of the boats log may have opened the hull to seawater, in which case Vandal may have been on the surface and started sinking.


Built in 1917, the 311ft Vortigern was a 1090-ton escort destroyer carrying three 4in guns, a 2-pounder and six 21in torpedo tubes. Torpedoed on 15 March, 1942 by the German E-boat S104 off Cromer in Norfolk, 147 crew were lost.
Vortigern lies in 23m, swept clear at 19.4m, and is so badly broken that in 1986 divers found a triple torpedo mounting, complete with torpedoes, more than 500m from the main wreckage at 53 05.437N; 01 22.098E .

So big was the explosion when this 1100-ton destroyer was torpedoed by U413 on 20 February,1944, 20 miles south-west of Trevose Head, Cornwall, that the Admiralty allocated two wreck numbers - one for the stern and one for the bow areas of wreckage. Though 93 men were rescued, 67 were lost.
The main wreckage of bow and stern are two miles apart, the stern at 50 29.40 N; 05 29.90 W and the bow at 50 29.953N; 05 25.337W. Only engines and part of the bow section stand more than 4m above the seabed in 55m.

A fish bomb is detonated - a warning of what can happen with munitions left on wrecks.
HMS M2, a submarine with its own seaplane aboard.
WW2 destroyer HMS Boadicea, torpedoed in 1944.
The first S-class sub HMS Swordfish disappeared mysteriously but was later found to have hit a mine.
A mine explodes
...thats munitions on wrecks and divers, says Craig English. His job with Ministry of Defence Salvage & Marine Operations includes trying to keep the two apart

ITS A COMMON MISCONCEPTION THAT MUNITIONS LYING UNDER WATER ARE INERT and pose little or no threat to an intrigued diver.
The Ministry of Defences Salvage & Marine Operations has extensive experience of wreck management. When dealing with wrecks such as HMS Royal Oak in Scapa Flow which have, or potentially contain, munitions, we have to be very cautious. By understanding the condition of the wreck, its possible to make an informed risk assessment before committing divers in a complex oil-removal operation.
Section two of the Protection of Wrecks Act 1973 gives guidance on dangerous wrecks such as the Castilion, which is a prohibited area because it contains explosives that present a potential danger.
Other wrecks are classified under the Protection of Military Remains Act 1986 as Protected Sites (divers can look but not touch or enter) but they may still contain munitions that are readily accessible to divers.
The Royal Oak is a classic example. Its designated a Controlled Site under the Act, so diving on or around the wreck is strictly prohibited, yet it still holds munitions.
The Jutland wrecks are now designated as Protected Sites under the act. Advances in diving technology have made them accessible to divers using both air and mixed gases, but they contain a lot of unexploded munitions.
World War One munitions were considered relatively unstable at the time of manufacture. Many contain Lyddite (picric acid) and Shellite shell-fillings. Picric acid has an ageing problem that causes metal picrates to form, and these extremely sensitive energetic materials
can be initiated very easily, simply by touching or moving. At this point the look dont touch ethos takes on real meaning.
TNT is more commonly found in World War Two-vintage munitions. Its a more robust shell-filling, but it too is sensitised by age.
Any change in the condition of a munition may change its sensitivity to initiation. Corrosion will weaken the case and reduce the protection of the explosive. A grit such as rust in contact with the explosives will sensitise it to initiation by impact.
So it will come as no surprise that the message here is DO NOT TOUCH MUNITIONS AND UNEXPLODED ORDNANCE.
Doubters among you should look at the photograph below right and on the opening page of WW2-vintage munitions doing what they were designed to do - go bang. Fortunately a diver did not initiate them.
And what we see below left is a WW2 shell recovered from the Castilion, and how potent it still is!
If wrecks designated under the Protection of Military Remains Act are known to be disturbed by divers, the right is reserved to use the more restrictive Controlled Site designation. Underwater activities within a specific distance of the wreck would then be virtually prohibited unless a licence is granted by the MoD.