It'll stand up to salt much better than it stands up to sunlight, I wash my (hypalon) boat off every time, but I can & I'm doing the trailer anyway so it's no great shake. I wouldn't get too hung up on washing the boat off each time out. I wouldn't want salt to build up in the engine or on the mechanical bits though, if I could avoid it.
Rule#2: Never argue with an idiot. He'll drag you down to his level & then beat you with experience.
Rule#3: Tha' can't educate pork.
Rule#4: See rule#5