When my son was in the Navy on a distroyer and on deployment in the gulf they lent support to SEALs as they boarded ship carring embargoed oil. He said that they slept on thier fantail and that they were kept separate from the crew and that they had a roped off area and an armend guard.
He explained it to the fact that you all had diffrent missions and never mingled.
I digress so I can see where you would not have the oppertunity to work out even though all ships have a weight room or run because some ships don't have a lot of room.....