Maybe make sure you have a UV filter, that way you won't get the front of the lens all misted, and the salt spray won't have the opportunity to do anything to the front lens element.
Also, if you change any lenses, do so inside in the cabin instead of out on deck. Duh!
In terms of 'cleanup', mostly I'd say the front element (or filter that you have on), maybe the inside of the view-finder using a Q-tip, and maybe a very light wiping with a soft cloth that's just a little damp to help clean off whatever film of salt spray that's on it.
I live in LA, and bring my camera down to the beach & near the water all the time, I generally haven't had any problems at all with it getting a bit misted. I just pop off the front filter, get it really clean, and good to go