Isn’t one the nicknames for subs, pigboats?
On our beloved old diesel boats back in the 60s...no showers, usually only a basin of water to wash with once a day. And as a lower-ranking and non-rated, non-qualified seaman you "hot racked" and "messed cooked". There was little room in the passageways and you squeezed in after battery for meals in two shifts. It was also very much a locker room with a lot of naked bodies running around (wouldn't mind seeing women here but bet they would mind seeing men back then). There are still countries (Dutch, Germany, Sweden, Denmark, Norway, Poland, Russia, Japan, S. Korea etc.) that operate diesel boats because they are quiet. We have only one left: USS Dolphin.