Amazing!! I personally would not want to be standing on the outside of that thing!!
They are safety -lined to the deck. Also those vests you see them wearing are called Float Coats. They are basically life jackets that auto-inflate when they hit water and have a water activated glowstick on them as well.
They are basically the same thing you see flightdeck personnell wearing in any shot of a carrier's flightdeck you see on TV.
Can't tell you which sub that was as I do not see a hull number and I am not sure I could tell you in any case.
Though based on the pics its a Los Angelos class attack sub or SSN.