Lengthy periods on a ship means isolation and when men and women experience that isolation you can expect all the rules to go right out the window. It doesn’t matter what sorts of restrictions or rules or even punishments are administered. Men and women will have free sex as often as they can get away with.
It’s one thing to be deprived on land and quite another to be so at sea and desperation combined with human nature will pay about as much attention to any rules as an animal would. Indeed the very drives that people contend with are quite animal like. It’s clear then that rules are simply understandable deterrence efforts made with the knowledge they’ll be broken. It can’t be stopped and Free fucking will be had as often as it can be and under any circumstances it can be. It might also be noted that that very nature is being actually counted on when the time comes to explore another very different sea, that of the stars. In order to survive quite literally as a species for any length of time there would necessitate men and women breaking those rules. Such could be said that it might even be enforced. Now that would be an interesting switch. It could be that premiums would be given to couples that could endure the training needed to operate spacecraft and the conditions of space travel. Being able to procreate and populate among the stars might even be the rule of the day itself if that time is to come.
Human beings will eventually populate themselves into extinction without some viable alternative. The planet has only a finite amount of space, and humans an infinite ability to breed. That dilemma will have to be dealt with at some point. Fortunately for man kind the answer is already in hand, at sea. People will just do what they do, in the farthest reaches, of outer space.