What character traits are critical be a successful submarine crewmember?

The ability to work well in small spaces.

You have to be batsh*t crazy! Anyone who serves on a ship that purposely sinks itself has to be certifiable. (I know, I know....the crazy ones call it "submerging", but I know sinking when I see it!)
This coupled with an incredible ability to become nose blind are the most critical traits of a submariner.

Dedication to always perform at your best without holding anything back. A submarine doesn't have a crew member so much as it has family and new people. When the new people can be trusted and have been properly trained and educated, they then become family.

CH (MAJ) William Beaver
Knowing how to work with a team!

Ones I could never have. I went to Groton every summer growing up and have been on the Nautilus more times than some. I have always been fascinated by subs, but I would not have been able to be a Bubblehead. The cramped quarters wouldn't have been the issue, my issue was worrying about sinking. A ship sinks and you have life boats and vests. A sub sinks, and you have to rely on a DSRV. No thank you.

Some advice from those who know??