I knew a chief that did.. he even shaved while the ship was underway.... he would just make sure to shave in the evening when the daily work hours were done.. although he DID have a mach just incase he had to shave on the fly.. When I was in the Navy there were time when we had to shower in salt water so my advice on that is during water hours either don't use your straight or take every precaution to protect the blade from the salt water... If you aren't use to shaving with your straight while movement is going on (My sone is at my feet when I do so i am use to him bumping into me and stuff with out getting nicked) then it would be a very good idea to shave when the ship is somewhat stationary until you get the hang of it. That chief was so good he could shave in 13 foot swells... Personally I would only use the straight at times when you can actually take your time. At the time when I was in I wasn't using straight razors so I have no personal experience, and the chief that i saw using one was only on the ship for a little while, so my info is just speculation at best.

As far as what to take... Usual stuff, blade, strop, some honing stones just in case, alum block definitely, and a shaving soap that will lather in salt water... They are hard to find, but if you have a shaving soap that is made with lotsa coconut oil and caster oil it will lather every time no matter what kind of water. I personally haven't used Poraso... The draw back is high amounts of coconut oil is drying to the skin so make sure to have some glycerine that you can add to it... of course bring your scuttle and brush too. If you don't have your sea legs yet.. don't even try.. until you know how to "Gyro" (for lack of a better word) your body while the ship is moving then it will be futile at best to even try. even BIIIG ships move... I was on a guided missile cruiser and all of us knew how to walk down the Pway's even if it meant putting your feet on the bulkhead for a roll or two.. But that was the Atlantic side.. and of course anyone int he Nautical military knows there is a BIIIIG difference in the Pacific and Atlantic Ocean. Shooter is definitely right though.. you have to protect everything from the salty air too.. OH.. and MAKE sure to keep your strop protected too.. salt air will dry out leather like nothing else so you will probably need to care for your stop more often..