John Gaimes was born on 10 April 1886, the son of Ada Bancroft Gaimes of Tonbridge, Kent, and the late Henry Austin Gaimes. He joined the Royal Navy in September 1901.

After time in HMS ALBERMARLE, HMS MAJESTIC and the Royal Naval College, Greenwich, Gaimes joined submarines in January 1909 and, after time in the Submarine Depot Ship HMS THAMES, his first command came in October 1911, when he was appointed to HMS A9 as a Lieutenant. Commands followed of B3 (September 1912) and C37 (March 1913), the latter in Hong Kong. He was still in Hong Kong, although not all the time in command, until he returned to Britain in November 1916. In May 1917, now a Lieutenant Commander, he took command of E4. Command of E45 followed and, during this appointment, Gaimes was awarded the DSO, the citation for which read:

‘Carried out minelaying operations in enemy waters on 23rd, 24th & 25th April 1918 and was informed his conduct was fully approved by their Lordships.’

By July 1918, Gaimes was commanding L14 and, after time in HMS DOLPHIN, he took command of K5 in April 1920.

HMS K5 was lost with its entire crew whilst diving to attack Battle Cruisers during a tactical exercise on 20 January 1921. The reason for the loss was not established, but it is believed that the submarine exceeded its safe diving depth and broke up. John Gaimes is commemorated on the Portsmouth Naval War Memorial on Panel No. 32.