^This.I'd be way more concerned about long term effects of corrosion from salt water.
Door hinges s d the rear fenders may get sand blasted. Just be sure to wash it all off before it gets ground into the paint be anyone touching it or getting in/out
What do you use?Undercoat/rustproofing, being doing it to all my vehicles since 1980, no rust. Rinsing after each beach use also helps. We live a block from the ocean. My cousin coats everything underneath with POR 15, time consuming, but this also works.
Ziebart dealership or fluid film. I coat my oil and transmission pans with POR 15. Rinse after beach use; or at least once a week during fishing season.What do you use?