From the Times obituary of Captain Crawford:
Under Crawford, Unseen launched 18 torpedo attacks, yielding 15 hits and 11 successes. She also survived 199 depth charges — no wonder the consumption of rum over 257 days at sea during 11 combat patrols was seven gallons, seven pints and six tots per man.
Well, not so much really. Standard rum issue was one eighth of a pint per man per day. So the rum issue there was in fact two issues a day, thereabouts, allowing for the occasional Temperance declared.
Not low, no, but by the standards of the time (there was no other booze on a submarine of course) not all that high either.