No, I don't suppose gold corrodes much, but seawater damages it as a numismatic object, as do the cleaning practices of the finders. Great for jewelry and souvenirs, but only interesting as type coins to me. There doesn't seem to be an end to it, either. How many 1922
Peace dollars have been slabbed? I'd bet that easily as much treasure ship booty could be slabbed, if it hasn't been already. And even if it was scarce, it still wouldn't be all that interesting to me. Scarce US numismatic gold in better condition (which interests me a lot more) sells at bullion price. Once again skillful marketing trumps arcane topics like numismatics and archaeology.
Holding one of these coins, or keeping one in my safety deposit box, will never turn me into Blackbeard, Johnny Depp or Walt Disney. Maybe Donald Duck.