There is really good book covering an S class sub operating in the med during the war; Crash Dive, In action with HMS Safari.
I'd really recommend it was written by leading telegraphist, Arthur Dickison whom kept a diary of time onboard the submarine from leaving Scotland, patrolling in the med etc. wonderful insight into life onboard and offboard a submarine during WWII
Some info about the submarine can be gained here too:
http://home.cogeco.ca/~gchalcraft/sm/page10.html#Safari