Marine archaeology has advanced considerably over that last 50 years. My last visit to Mary Rose was early on in the restoration. Much has been done since those early days.
Kansas City has a 1850’s steamboat, the Arabia, that sank in the Missouri River and was left in a farm field when the course of the river changed. The preservation is remarkable, some of the foodstuffs were edible and the trade goods looked like they just came from the factory. The ship was well preserved, but only a portion of it was conserved. Well worth a visit and closer to Portsmouth for those on this side of the pond.