In all seriousness...you might check some navy sites...see what Submariners do...they spend about the same time submerged as in jump...actually many times more....
Ok, during our 87 day submergence doing things submarines do we...
1) Stood watch 6 on, 12 off
2) Worked on systems that were constantly broken
3) Came up with new ways to fix things that were still broken no matter what we already did.
4) Worked on qualifications for the next higher watchstation.
5) Watched the same damn movies over and over again
6) Those that were qualified, slept.
7) Those that were unqualified, qualified.
8) Figure out a way to tell the guy who sleeps under you that his feet carry a stench you'll remember till the end of your days in a nice way so he doesnt kick your a$$.
9) Bring a laptop and mess with it.
10) Read a few books, sub had a small library (40 books or so)
11) Did our job, prepped charts, fixed stuff, screwed with our shipmates minds, sent the new guys for PEN-15 and ID-10-T forms or TM Punches. Oh, and batteries for the sound powered phones.
RV