In 1876, divers engaged by the then Countess of Erroll recovered two more cannon and a large anchor which the Countess presented to Queen Victoria. They were for many years kept at Balmoral, but were ultimately presented by Edward VII to the Imperial Services Museum in Whitehall. When the Museum closed down, the 23rd Countess of Errol was allowed to buy them back and they returned to Slains. In 1880 a London firm raised another large cannon and conveyed it to London, but its present whereabouts would be difficult to trace. The rate of disintegration of a submerged wooden ship will vary with the depth.
Iron rusts from contact with air bubbles and dissolved oxygen in water.
Oxidation will proceed quickly of located amongst breaking waves. Silver undergoes a chemical reaction turning into black silver sulphide. If silver is in contact with, say a cannon, it will survive in very good condition, as electrolytic action will pass it by to attack the more active iron. Gold is never changed by chemical action under the sea. I'd like to join you . . .