I've just seen "Das Boot" for the third time and I'm really wondring if they had a shower onboard of the type VIIC u-boats? If no, how did they keep their bodies clean? I mean a "Feindfahrt" would sometimes last weeks/months.
EDIT: Thank you so much for your interesting answers :) I've got another question regarding u-boats. When submerged, the crew is practically blind. Assuming they didn't dive too deep and the weather was good: Did the Kaleun ever use the periscope to check out the surroundings under water? I mean like leaving the periscope below surface and e.g. checking for mines or depth charges (and then steering away from them)...
By shower, I'm presuming you mean something like a dedicated shower unit somewhere in the sub? In that case, no, there wasn't. A shower head could be connected to a sea water collection line if need be, however. Though this was most often used for purposes other than personal hygiene.
Typically, U-Boat crews were conditioned to go without showering or shaving throughout their patrol since fresh water was a precious commodity that could not be easily replenished while on patrol, and in addition, the extra space needed for showering facilities (and to heat water) would have taken up precious space needed for other supplies, crew or equipment. The crew was issued deodorant and a special type of soap to help them keep clean while preserving their supply of fresh water. While obviously not a solution all the time, the crew could also indulge in bathing (well swimming) in the sea, weather and combat condition permitting.
No. They had one toilet with a contrapted, pressurized head. This was the cause of loss of at least one u-boat, after a mixup in the valves caused sea water to flood.
The IXs were luxurious in comparison, having two toilets. Pity that one was always occupied with fresh produce at the beginning of the patrol and only was usable when it was consumed.
They Type XXI had arrangements for a shower for the men and greatly simplified the arrangements for potable and wash water compared to earlier designs. The USN evaluated these systems rather poorly, as seen in this report after the war.The USN put an early effort into hygiene and habitability. Thus they were installing showers in their submarines in the 1920s as well as experimenting with air-conditioning and freezers. While service on an American boat was far from a carnival cruise (the showers were usually filled with fresh food), this focus on habitability greatly helped when in serving in the tropics.
Sources
Jackson, Stephen Leal. The Men: American Enlisted Submariners in World War II : Why They Joined, Why They Fought, and Why Then Won. Indianapolis, Ind: Dog Ear Publishing, 2010.
Weir, Gary E. Building American Submarines, 1914-1940. Washington, D.C.: Naval Historical Center, Dept. of the Navy, 1991.