Spain's ambassador to the United States, Jorge Dezcallar de Mazar, was expected to watch when the two Spanish military C-130s take off from a Florida Air Force base with 594,000 silver coins and other artifacts aboard, packed into the same white plastic buckets in which they were brought to the U.S. by Tampa, Fla.-based Odyssey Marine Exploration in May 2007.
It wasn't clear when exactly the planes would depart or where and when they would land in Spain. With much at stake, the Spanish government requested a high-security operation and key details arranged with U.S. authorities weren't disclosed.
Odyssey made an international splash when it discovered the wreck of the galleon, believed to be the Nuestra Senora de las Mercedes, off Portugal's Atlantic coast near the Straits of Gibraltar. At the time, the coins were estimated to be worth as much as $500 million to collectors, which would have made it the richest shipwreck haul in history.
The ship was believed to have had 200 people aboard when it was sunk in the attack while nearing the end of a long voyage toward home.
Spain was going ahead with efforts to move the treasure despite a last-ditch, longshot claim to the treasure by Peru.
On Thursday, the Peruvian government made an emergency appeal to the U.S. Supreme Court seeking to block transfer of the treasure to give that nation more time to make arguments in federal court about its claim to being the rightful owner.
Peru says the gold and silver was mined, refined and minted in that country, which at the time was part of the Spanish empire. The appeal was directed to Justice Clarence Thomas, who did not indicate when he would respond.
U.S. courts had previously rejected claims by descendants of the Peruvian merchants who had owned the coins aboard the Mercedes.
"Peru is making the same arguments that have been rejected at every level of the U.S. courts," said James Goold, a Washington attorney who represents the Spanish government. "There's absolutely nothing new in it."
The head spokesman for Peru's embassy in Washington, Rodolfo Pereira, declined to comment Thursday on the appeal.
Spanish officials said last week the planes would leave by Friday, and MacDill authorities planned a news conference on the base Friday morning with the ambassador and other officials. The planes were expected to be already loaded with pallets holding the white plastic buckets filled with coins.
Odyssey - which uses a remote-controlled submersible to explore the depths and bring the tiniest of items to the surface - had previously argued that as the finder it was entitled to all or most of the treasure. The Spanish government filed a claim in U.S. District Court soon after the coins were flown back to Tampa, contending that it never relinquished ownership of the ship or its contents. A federal district court first ruled in 2009 that the U.S. courts didn't have jurisdiction, and ordered the treasure returned.
Odyssey had argued in federal court that the wreck was never positively identified as the Mercedes. And if it was that vessel, the company contended, then the ship was on a commercial trade trip - not a sovereign mission - at the time it sank, meaning Spain would have no firm claim to the cargo. International treaties generally hold that warships sunk in battle are protected from treasure seekers.
Odyssey lost every round in federal courts trying to hold on to the treasure. In a court hearing Feb. 17, the company was ordered by a federal judge to give Spain access to the treasure this week to ready it for transport. Odyssey said it would no longer oppose Spain's claims. Meanwhile, the court also ordered that Odyssey had to turn over some coins and other artifacts that are still in Gibraltar.
The company has blamed politics for the courts' decisions since the U.S. government publicly backed Spain's efforts to get the treasure returned. In several projects since then, Odyssey has worked with the British government on efforts to salvage that nation's sunken ships, with agreements to share what it recovers.
The company has said in earnings statements that it has spent $2.6 million salvaging, transporting, storing and conserving the treasure. But it is not expected to receive any compensation from the Spanish government for recovering it because the European nation has maintained that the company should not have tried to do so in the first place.
Goold previously has likened the salvage of shipwrecks for profit to diving for souvenirs on the wreck of the USS Arizona in Pearl Harbor, Hawaii.
In Madrid, the Spanish Culture Ministry recently said the coins are classified as national heritage and - as such - must stay inside that country where they will be exhibited in one or more Spanish museums. It ruled out the idea of the treasure being sold to ease Spain's national debt in a country grappling with a 23 percent jobless rate and a stagnant economy.
