1,
What is current thinking on recovery of the alleged treasure lost by King John in the Wash?
2. (Relying heavily on memory; Penguin book on Mesopotamiian excavation - Henry Rawlinson? ). What chance of locating / recovering tablets etc lost in the Euphrates or Tigris when a raft capsized?
Given that due to land reclamation the wash is only a fraction of the size it was when king john supposedly lost his treasure It is impossible to know just where he lost it let alone recover it. The only hope of ever finding any of it is if somebody gets lucky with a metal detector.
depends on what the tablets were made of - if clay, no chance I would have said. Also whether lost recently or in ancient times. As for the Wash, pretty much needle-in-a-haystack stuff; as paddywak says, it'll only happen if some gets lucky.