I'd like to make two points. First off, Lex Parsimoniae is correct. To further add to his response, it is not only a question of bunking. Even though a person may become a submariner, they are still required to advance within their individual trade. If certain trade quals are not met prior to joining boats, it will be harder to load you on a career course in the future (which may be surface-centric) in order to advance in your trade.
The second item I would like to address is Chief Stoker's comments about sea time. I have never heard any submariner brag about not having to sail. Since I've joined submarines I have sailed as often, if not more than I did on skimmers. Even with only having one boat running, I've still managed to put to sea, as a minimum, for about 4-6 months a year. Although you hear much in the media about submarines being "not operational", please do not confuse that with not being at sea. By operational they are referring to weapons readiness. In one recent year alone COR conducted work ups, a trip across the Atlantic, several international exercises, an arctic sovereignty patrol and an operational narcotics interdiction patrol. In one year. In fact COR got the CDS unit commendation. We all know guys who avoid sea-time. I've seen my share of "NATO knee" when I was in the surface world - and yet I would avoid making sweeping assertions about malingering there. As for the hotels - I'll start feeling guilty about hotels in foreign port (and SA - can't forget the SA) when subs get fitted with cabins, email, internet connectivity at sea, television sattelite, satellite telephones, beer machines, the ability to do laundry, toilets that don't require you dissecting your own feces with a high-power salt water gun, and enough fresh water to shower everyday.