HM Submarine Thermopylae
Thermopylae was laid down on 26 October 1943 and launched by Mrs Hobbs on 27 June 1945.
In 1951, Thermopylae returned to Chatham for a major conversion. During the refit, the boat was lengthened by 14 feet.
Whilst operating in 1952 a wave swept the bridge and the Officer of the Watch was knocked unconscious.
Thermopylae was the first boat to be fitted with the new shapes dome on the bow. This enclosed the 171 which it was hoped would give accurate hydrophone bearings. It proved to be unsuccessful and in 1958 was replaced with the 187 set.