Freak storms, the gall of audacious pirates or the guns of rival navies all sent them to the bottom while they sailed the perilous India Run, bringing treasures from Spain's colonies in the Philippines and the Americas. Marine archaeologists believe that lying under the waves in the Mediterranean alone could be sunken treasure worth ¿100bn (£73bn), but all acknowledge the real value will probably never be known. Elsewhere, scattered around parts of the globe, in the Atlantic, Caribbean and Pacific, lie more sunken millions. Now, hundreds of years after the gold baubles and silver ducats went to the bottom of the briny, there is an international battle to lay claim to this treasure.
Centuries on from the Spanish conquistadores, their modern descendants are determined the millions in gold and silver will not be claimed by 21st-century pirates who employ hi-tech gear to retrieve the treasures.
This is an update on earlier stories relating how countries are attempting to lay claim to wrecks outside of their territorial waters by arguing that they were, for example, Spanish ships then and should still be Spanish ships now.