Gary's right, the laws of the sea are being increasingly tested by the laws of the land.
recent law changes in Oz have made it an offence not to hand over a cash find to the Police. Subsequent changes then were made that if the money isn't claimed, it goes to the Govt. All other property goes to the finder after a statutory period for the real owner to come forth.
I think I am due some of these riches. I'm pretty sure I have some kin-folk who were on that ship when it happened to sink....I'm sure of it. Who do I sue?