Lots of guns and lots of ammo. Everyone knows how to shoot them and if they are not on home soil, they are armed, manned and at the ready. Pretty intense.
They still navigate with paper charts (lots of electronic stuff too but they manually plot each course).
Duck under and step over a lot of places like bulkhead doorways and stuff.
These guys really know the meaning of multi-tasking. The cook is also the fitness officer and the arms guy (in charge of distributing and keeping track of all the guns and ammo).