In the Florida keys in 1972 a Cherokee from our flying club ditched in shallow water after an engine failure. No damage,no injuries, just wash and rinse to get the salt out, should be good to go, right? Nope! It was Friday afternoon and the feds up in Miami told us to put a guard on it 24/7, don't let anyone touch it, they'd be down sometime next week to take a look at it.
Long story short, after one weekend in the water it was a total write-off. Instruments shot, engine shot, airframe structure corroded everywhere chafing or fastener holes had penetrated the cladding.
Cheers,
Wes