An appellate court has upheld a lower court decision that ordered American treasure-hunter Odyssey Marine Exploration to return to Spain some 594,000 gold and silver coin valued at roughly $500 million recovered on the ocean floor from a sunken Spanish Galleon. The United States government supported the Spanish in the claim and the coins are supposed to be returned to Spain within ten days.

Here is how the Court described the case in an earlier ruling:

Odyssey is a deep-ocean exploration and shipwreck recovery business. In 2006, Odyssey began what it called the Amsterdam Project, researching ships that sank in a heavily-traveled area, which included an area off the coast of Gibraltar. Odyssey developed a list of target vessels to search for, one of which was the Nuestra Senora de las Mercedes (Mercedes), a Spanish vessel that sank in 1804. According to Odyssey, it “recogniz[ed] that Spain may have had a cultural (if not legal) interest in vessels that may be located within the Amsterdam area, [and] invited Spain to participate in the project.” Odyssey’s Resp. to Spain’s Motion to Dismiss, Dkt. 138 at 3. Odyssey’s CEO and counsel then met with a representative from Spain’s Ministry of Culture. What occurred at the meeting is disputed, but both Odyssey and Spain agree Spain did not give Odyssey approval to salvage any sunken Spanish vessels.