Most importantly you have to flush the motor and livewells/bilge with fresh water as soon as possible from getting out of the water each day. Also washout the trailer as much as you can. Before you go be sure to grease the bearings well and spray any wiring connectors in and out of the boat with white grease. Silicone spray or wd40 under the hood is ok but it will smell when it heats up. White grease on all the cables/linkages will be good insurance agaist the salty air/spray. Be sure to spray plugs to depth finders and even a shot in the keyhole wont hurt. Take your engine flusher and a garden hose if you'll have access to a tap. I have put the flusher on and forced water in it at the carwash in a pinch to flush the salt out.
Three-fourths of the Earth's surface is water, and one-fourth is land. It is quite clear that the good Lord intended us to spend triple the amount of time fishing as taking care of the lawn. :rolleyes: