Christians in 1st century: the world is ending very soon!
Muslims in 7th century: the world is ending very soon!
Mormons in 19th century: the world is ending very soon!
Given enough apocalyptic religions one of them would be right, but I think that religion doesn't exist yet.
Hopefully he coordinates with all the local governments having jurisdictions over the waters surrounding the shipwrecks before disclosing the locations, otherwise they will very quickly get poached for low background steel illegally.