Got this statement off of, royalnavy.mod.uk Submarine service FAQs . Where do you sleep? On British submarines there is an area set-aside as the "bunk space", which contains all the beds or bunks for the crew. Each bunk is approx. 2 metres long by 1 metre wide by 1 metre high, and is often shared by two men who are in different shifts or "watches". The principle is; as each man gets up to go "on watch" he rolls up his own sleeping bag, and rolls out the sleeping bag of the man coming "off watch". During the normal operations of a submarine the sleeping area will only be lit by dim red lights, so as to enable the off watch sailors to sleep. The only man who has his own room, or cabin, is the Commanding Officer. we didn't hot bunk back thirty odd years ago! OK sometimes, rarely, but now in the 21st century, I don't believe it! surely the author is swinging the lamp, jackanory style.