I do know about the aircraft carrier USS Nimitz.
At sea there are two 12 hour shifts for regular work shifts. In addition there may be a watch schedule. Sometimes the watch will coincide with the 12 hour work day in whole or in part. When deployed on a long cruise you might have a three to six day port call, then 20 to 30 days at sea. In port overseas there was three section duty. The carrier I was on never docked in port when deployed, instead we anchored just outside the port, ready to get underway. With 3-section duty, 1/3 of the crew stays aboard their duty day (24 hrs) to perform watch station duties. Those not on duty can go for Liberty when liberty call is announced on the 1MC. Enlisted ranks E-6 and below had to be back to Fleet Landing by midnight, E-7 through E-9 01:00, Officers and Warrant Officers 02:00.
My first six month scheduled Med Cruise had port calls. Then Iranian students took American Embassy staff hostage. We had been in the med for 6 months when that happened. The ship was sent from its final port call in Naples, Italy; five days and nights at 30 kts around Africa, to the Gulf of Oman Naval Zone of Operation (GONZO station). We were told we would be there for a month, but that was extended each month until we had been there for just over 5 months. There was a west coast carrier with us at GONZO, they would be relieved once a month by another west coast carrier. The Nimitz got holiday routine (flight operations secured for the day) every other Sunday, with a steel beach picnic.
We came back in late May to Norfolk VA and had to have a quick turn around in the Naval Shipyard in Portsmouth, VA and then went on a two month deployment to the North Atlantic.
Some navy ships never or hardly every leave port, we barely stayed in port. If we weren't in the ship yard we would deploy at least every other month for two weeks or more for some type of training and flight operations.
We never got long breaks in between deployments. Nuclear aircraft carriers will get a couple of years straight in the shipyard for mid life refueling at 25 years. When I was aboard it was 22 years left before refueling.
I had a cousin in the Navy the same time that I was, stationed on a Gator freighter, that never left port in San Diego. He told me they tried to go on a Westpac cruise but had engine room troubles and had to be towed back to port.