HMS J6

On 15 October 1918 J6 was on patrol off the Northumberland coast when she was spotted by the Q-ship Cymric. The captain of the Cymric, Lieutenant F Peterson RNR, mistook the identity lettering on the conning tower of J6 for U6. Assuming U6 to indicate a German U-boat, Peterson raised the White ensign and opened fire on J6.^[3] J6 tried to signal, but the signalman was killed. J6 fled into a fog bank, but Cymric located J6 again and sank her.^[4] J6 sank near Beadnell. During a roll call, eight crew members could not be found. The remaining crew members had closed the escape hatches to prevent the submarine from diving for as long as possible. Therefore the crew members still inside the submarine could not escape when the ship began to dive.^[5] After a number of direct hits, J6 sank. It was only after the survivors were seen in the water when Peterson and the crew of Cymric realised their mistake and recovered the survivors. Of the crew of J6, 15 were lost;^[6] a subsequent court of enquiry found no action would be taken against Peterson.^[7] An order under the Official Secrets Act prohibited mention of this incident until 1969.^[8]

Late in 2011, it was announced divers had discovered her wreck 40 miles (64 km; 35 nmi) off the coast of Seahouses, near the village of Blyth, from where J6 had departed before it was sunk.^[9] In the summer of 2013, the Polish Navy salvage ship ORP Lech, searching for the wreck of the Polish submarine ORP Orzeł, surveyed and officially confirmed the identity of J6.^[10]

• Akermann, Paul (1989). Encyclopedia of British Submarines 1901-1955. Periscope Publishing. ISBN 978-1-904381-05-1.