I deployed on a sub five times in four years, so I'm maybe not the best one to give an example. For us, we got used to the 'no outside' within a day or so as there is always so much else to do.

Long term, you make friends, come up with portable hobbies, and just dig in to the job for a while.

Consume as much food and booze as possible to drown your depression caused by being crammed on a disease-ridden ship with 3,000 strangers.