Other aspects of submarine duty are that you don't get out into open air for long periods of time and the spaces are fairly restrictive, which would get a little claustrophobic over time even if you aren't prone to that ordinarily.
I think taller people are handicapped because of all the low hanging gear.
I don't think there were any guarantees, but I do believe the submarine service upgrades the food service so the crews eat really well. In my experience, Navy food in general is better than average, better than you get at a standard diner or cafeteria. I never had any complaints, and we had some really (really) long deployments. Though, of course, the coffee is terrible.
I always liked it on the mess decks when the bridge came over the speaker and said, "Stand by for heavy rolls." Meaning rough seas, but sounding like they meant the bread course.
We took on supplies by underway replenishment, moving fuel, supplies, and sometimes people across on a line (rope) and pulley. Because a power winch presents a danger to peoples' limbs, the power is supplied by the crew heave-ho'ing in a row on the ships weather decks. The supply ship is an oiler which is much bigger than the ships it supplies.