One of the rules....
Very rarely will hit actually run in the saltwater....for obvious reasons... BUT sometimes I will run close if the sand is hard enough, and believe me, I wash the undercarriage after each run when that close...
Having been the victim of several rotted floors, ties, runners, etc I am very careful..i.e getting old...
The LR has held up the best so far with regards to the wear of the beach...
Still, the best truck I ran was my old 65 CJ5... top speed 50MPH on highway... Crazy gear ratio, could walk outside next to it and steer at the same time.. no roof, rotted, beefy, but GREAT...