Cyril Mann joined the Royal Navy at HMS GANGES on 21 December 1916.  After service in the battleship HMS MONARCH, the battlecruiser HMS TIGER and the cruiser HMS CANTERBURY, he entered HMS DOLPHIN for submarine training on 20 November 1924. He was then drafted to the Anti-Submarine School at Portland for the hydrophone operators’ course and thereafter to HMS H27.  

On 30 December 1925 he departed for the China Station on board HMS VINDICTIVE where he served in HMS L7.  He returned home in mid-1928 where he was drafted to the depot ship HMS VULCAN for HMS H47 on 3 September 1928.

He lost his life when HMS H47 was sunk in a collision with HMS L12 off St David’s Head, Pembrokeshire on 9 July 1929.