We live by the ocean, only a couple of miles inland. Also have taken several trips to ocean front campgrounds where we were less than 100 yards from the beach. Never had an issue. We keep the rig clean and waxed, and when parked long, we keep it covered. But it doesn't have any issues from the salty sea air over a few days. Same with our vehicles.
2015 Thor Chateau Super C 33SW
F550 Chassis, 6.7L Powerstroke