My husband is stationed aboard a submarine here in Bangor. I am a Navy wife and do have experience touring, visiting, and talking with crew members aboard the sub. I think that yes, a woman may be physically qualified, but I strongly doubt that most, if any, women are emotionally qualified to serve aboard a submarine. My husband is gone months at a time, with no mail drops, no port visits, not even surfacing. When you put men and women together in close quarters, that is asking for trouble.
Submariners have a total different life than surface crews.
And even on surface ships the amount of women that become pregnant is big. Anyone with any common sense would be able to see that this would not be smart. Besides, in a war, I wouldn't trust a female to be unemotional. I think if a female were told to fire a torpedo, she will pause and think about how she is killing someone. That split second of hesitation could get the rest of the crew killed.