The battleship HMS Royal Oak was sunk by torpedoes from German submarine U-47, under the command of Prien one of the three recognised U-boat aces of World War II, in the early hours of October 14, 1939, which had penetrated the British Navys main anchorage at Scapa Flow in Orkney (Scotland). 

HMS Royal Oak was sighted. U-47 fired three salvoes. The first landed a minor hit which the crew of the battleship mistook as a minor internal explosion, rather than a sign of attack. Despite the second salvo missing, the confusion surrounding the first hit gave Prien time to return to his original firing position, reload, and fire again. This third salvo delivered the fatal hits. The ferocity of the explosions caused the ship to heel over alarmingly and she sank with frightening speed.

A total of 834 men lost their lives when the ship went down in minutes after being attacked at anchor. Most were killed by fire, many as they slept in their hammocks. Of those who escaped, few survived the freezing cold sea.

These images are artist impressions of how she now lies (www.hmsroyaloak.co.uk)

HMS Royal Oak capsized as she sank and now lies almost upside down in 33 metres of water. The up-turned hull is the shallowest point of the wreck and is just 12 metres below the surface. The weight of the wreck is resting on the superstructure and, as a result, the bows are three metres clear of the seabed, with the anchor chains hanging down in big loops.

This video was filmed in October, 2013, while the wreck was being checked by Northern Diving Group (Royal Navy Team) who are permitted by the Royal Navy to dive on the war grave.

This video is a 3D visualisation of the wreck of HMS Royal Oak on the seabed of Scapa Flow, Orkney (Scotland, UK), using a SeaBat 8125 multibeam sonar system.

These are some photos of HMS Royal Oak which were taken around the time of the 60th anniversary of her sinking and have just been released prior to the 70th anniversary in 2009.

Two of the torpedo holes from the inside (www.hmsroyaloak.co.uk)

On the seabed at 30 metres the cover of the 15" gun breaches has fallen away leaving the breaches visible. The 15" barrels lie crushed underneath the wreckage (www.hmsroyaloak.co.uk)

The breach cover is in the centre, the 15" barrels to the left and the carly raft to the right (www.hmsroyaloak.co.uk)

The gunnery spotting top above which was the rangefinding equipment (www.hmsroyaloak.co.uk)

The Admiral's Barge was used to transfer officers to and from the ship. She now lies on the seabed in 30 metres of water (www.hmsroyaloak.co.uk)

Anti aircraft guns (www.hmsroyaloak.co.uk)

Twin 4" guns (www.hmsroyaloak.co.uk)

6" side armament (www.hmsroyaloak.co.uk)

This video marking the 75th anniversary of the tragic sinking of the Revenge-Class battleship, a shore side ceremony at the HMS Royal Oak Memorial in Scapa was followed by a wreath-laying above the wreck of the ship in Scapa Flow.