Speaking of corrosion, remember the effect of bacteria as well.
Entire ships of WW2, resting on the seabed are disappearing, and will not be there in some 100 years (?), for they are simply being "eaten".
The Titanic is falling apart and disappearing (Well, 1912), but even the Bismarck will fall pray to the same enemy.
Those are 3-4 km deep!
BTW, the Bismarck looks quite good still! Being a good looking vessel from the start, the hull is remarkably intact.
The HMS Hood is however torn up really bad.
(Resting not so far from where I live)
Uhhh, didn't want to hijack this into shipwrecks, - my point was meant to be that this P47 looks incredibly good if one bears in mind that it's been there for some 60 years!