My husband was in the U.S. Navy as a submariner in the mid-late 90's and into 00's. He was told when he chose submarine service that if he wasn't circumcised, he would'nt be eligible for submarine service. Basically, that if he wanted to join that particular branch, circumcision was mandatory. The main reason he was told, was that there can be conditions where they can be deployed for months at a time without ever docking anywhere, and in certain conditions, there was a possibility that fresh water would be conserved and wouldn't necessarily be available to use for personal cleaning issues. Combine that with such close quarters and many guys actually double bunking...where there was only one bunk and one guy had it when he was off duty and the other guy took it when the first guy went on duty, and you get the pic. about why there might be cleanliness issues with no water available....
I'm not sure why they didn't work towards fixing the problem all together though. I wonder if it was a JIC thing? Because DH said that in the years he was in, they never actually ran out of water for cleaning themselves, though they did frequently run out of toilet paper.