The submarine lies with its keel orientated at 160/340 degrees and has a height of 8m around the conning tower. It rests upright on a seabed of coarse sand, shingle pebbles and shells. In August 2000, a second part of the wreck was reported by divers some 200m to the south (see NPRN 240507).

Event and Historical Information:
This Mittel U type u-boat (ocean-going attack boat) was built by Kaiserliche Werft, Danzig. It was ordered on 23 June 1915 and laid down on 28 October 1915. Technical and configuration specifications are given as 215ft 9 1/2 in length, 20ft 4 1/2 in breadth, 12ft 9in depth; 998tons displacement submerged, 757tons displacement on the surface; armed with four bow and two stern torpedo tubes plus a 105mm deck gun; normal complement 44 crewmembers. Maximum operational depth 50m and with 45seconds needed to crash dive. Operational range 11,380nm at 8knots and 56nm at 5knts submerged.
It was launched on 22 May 1916 and commissioned on 26 February 1917 under the command of KapLt Rudolf Schneider. After a training period, it was officially assigned to III U-Bootflottille at Wilhelmshaven on 24 April 1917 and undertook five patrols sinking twenty-three ships (59,884gross tons) and damaged two others (7,621gross tons). Tragedy struck on its fourth patrol when, in heavy seas, Schneider was washed overboard. He was recovered, but died soon after from internal injuries. He was buried at sea by the crew. KapLt Rudolf Freiherr von Speth-Schulzburg assumed command and U-87 returned to Wilhelmshaven on 3 November 1917. On its fifth and final patrol, with von Speth-Schulzburg still in command , U-87 departed Wilhelmshaven on 8 December 1917 in company with U100 and a minesweeper. When the two U-boats parted company, U-87 headed to the western end of the English channel via the Dover Straits. It sank two small sailing vessels on the way - the 114ton Fowey-registered LITTLE GEM off the Casquest on 13 December and the 56ton Bridgewater sailing vessel CHARLES northwest of Guernsey on 18 December. On Christmas Eve, the 3238ton British steamer DAYBREAK (built 1911 and owned by Scarisbrick SS Co Ltd, West Hartlepool/Cardiff) was torpedoed and sunk 1 miles east of the South Rock Lighthouse. On 25 December 1917, U-87 attacked a convoy in St George's Channel (in particular, the 4812-ton British steamship AGBERI, see NPRN 274777). One of the convoy escorts was just 150yards away from the AGBERI when it was struck and turned to ram the submarine. The logbook of HMS BUTTERCUP, an Arabis class sloop, provides the a brief overview of what happened:
0242 SS AGBERI torpedoed
0330 While zig-zagging round Agberi submarine spotted on surface. HMS P56 engaged and rammed it. BUTTERCUP fired and hit conning tower.
0340 SS AGBERI sank. Submarine sank.
0500 rejoined convoy
The position given by HMS BUTTERCUP was 52 56N, 5 7W. Other accounts, suggest that HM Patrol Boat 56 dropped two depth charges and that the U-boat was forced back to the surface. Then the patrol craft turned and made straight for the enemy vessel, scoring several hits with her 6 pounder gun at close range until the U-boat was rammed, the bow of the patrol craft cutting into her pressure hull forward of the conning tower, so that the submarine broke in half. The U-boat's bow section remained afloat for about ten minutes although there were no survivors, both warships were able to look right into the interior of the submarine as the bow slowly sank. P56 was indeed left considerably damaged.
The Crew lost in U87: Adam, Friedrich, BootsmannsMt; Andermann. Fr, MaschinistenMt; Balleer, Max, MaschinistenMt; Brandt, Johann, Ob/Matrose; Collinet, Josef. Heizer; Dahlmann, Friedrich, MaschinistenMt; Dethloff, Otto, Ob/Matrose; Dost, Fritz, F T Gast; Fehsel, Herbert, Matrose; Fimpler, Adolf, Ob/Heizer; Gassman, P, BootsmannsMt; Grill, George, Ob/BootsmannsMt; Hansen, Robert, MaschinistenMt; Heinrich, Treidrich, Ob/Steuermann; Hilgenberg, Karl (LI); Hoffmann, W, Heizer; Hummel, Ernst, F T Gast; Jorgensen, J, MaschinistenMt; Koppehele, Fritz, Heizer; Krimme, Otto, Matrose, Kurth, Jacob, MaschinistenMt; Labahn, Hans, Ob/Matrose; Lehmann, E, BootsmannsMt; Lehmann, Walter, Maschinist; Ludwig, Edwin, Matrose; Mtodzikowski, Ob/Heizer; Patege, Paul, MaschinistenMt der Reserve; Peterman, H, Ob/MaschinistenMt; Preisker, Th, Ob/matrose; Reuting, Hermann, Ob/Heizer; Schnellke, H, Heizer; Schaff, paul, Matrose; Siebke, Johann, Heizer; Siebel, Johann, MaschinistenMt; Tetmeyer, Robert, Ob/BootsmannsMt; Viebranz, R, MaschinistenMt der Reserve; Wandt, K, ET Mt; Wille, W, Ob/MaschinistenMt; Willmer, Hubert,Heizer; Wodrig, Franz, Ob/Lt zur See (WO); and Zander, Paul, Heizer.
The submarine was included in the multi-beam surveys undertaken by Bangor University in 2018, as part of the Royal Commission's Partnership Project - 'Commemorating the Forgotten U-Boat War around the Welsh Coast 1914-18'.

Sources include:
Armstrong, P, and Young, R, 2010, Silent Warriors: Submarine Wrecks of the UK, Vol 3, pg97-101
Larn and Larn shipwreck database 2002
UK Hydrographic Office Wrecks and Obstructions Database. ? Crown Copyright and database rights. Reproduced by permission of the Controller of Her Majesty's Stationery Office and the UK Hydrographic Office (www.ukho.gov.uk).

WWW resources include:
http://www.uboat.net/wwi/boats/index.html?boat=87
https://uboatproject.wales/wrecks/u-87/
https://www.peoplescollection.wales/collections/966246

Maritime Officer, RCAHMW, March 2019.