Real-life Limits on Submerged time?
 

I'm watching War and Remembrance and the panicky captain asks about how long they can stay down. The officer replies 40 hours. This is a sub based outta Pearl in December of 1941.



That seemed like an awfully long time for me but that may be that I never stay submerged in-game anywhere near that long.



Was that kind of time possible with a full crew of that period?

It has been noted that some submarines have stayed down for up to 72 hours in this period with the aid of soda lime in some cases, the Germans Japanese and British faced the same problems the difference is the USN boats were a bit bigger than the contemporaries so they encase more air.