[meandog]

One thing to note, the Scandinavian naval forces all have coastal diesel boats meaning short duration patrols. Try sticking with a typical 90-100 day period at sea test period BEFORE allowing females on board U.S. boats. I’m certain also that good order and discipline will be affected by this decision as a sub crew is a team that requires the ability to get along among its members
There aren't many are no places for privacy on submarines. So "making woopie" isn't going to go down too well with the skipper and the rest of the crew, though I'm pretty certain it will be tried.

[longtermmemmory]

don’t some submarines have shared bunks (no rooms at all) where you take shifts using the same bunk?

the only justification for this is that they intend to now have submarines.