As a retired US Navy submariner and Independent Duty Hospital Corpsman who served onboard six submarines, I can shed some insight into this matter. Women have never yet served onboard submarines. Women shipyard workers at Electric Boat in Groton, CT and at the Portsmouth Navy Shipyard sued the Navy back in the 1980's because workers who worked at building submarines were randomly selected to go to sea during sea trials before delivery. Their promotions depended upon their going. Yet, women were prevented from doing so. The women won.
I was on the first submarine to take women workers to sea, the USS Michigan SSBN 727). They have since been doing so.
However, taking them as actual crew members has been problematical not for privacy issues (there is no privacy on submarines), but rather for medical reasons. The Bureau of Medicine and Surgery has prevented their doing so because of the possibility of ectopic (or tubal) pregnancy, a common enough occurence that could result in death if not surgically treated promptly. Submarines do not carry physicians onboard, even if they did, one would probably not diagnose the condition promptly enough to save her life, even if the surgical capabilities existed. They do not. This situation could be especially acute if it occurred under the polar icecap.
Apparently, BUMED removed its objections.
As for the Dolphins, there is an intense one-year qualifications program as well. The SWO and Air Warfare devices are based on the submarine qualifications program (The SWO crossed-butterknives did not come about until the 1970's). As for watches, coners (forward, non-nuke personnel) do not stand Engine Room watches.
Bill Morrison