Florida deep-sea explorers are asking a federal appeals court to overturn a judge's ruling that 17 tons of treasure recovered from a sunken Spanish galleon belongs to Spain.

Florida deep-sea explorers are asking a federal appeals court to overturn a judge's ruling that 17 tons of treasure recovered from a sunken Spanish galleon belongs to Spain.

The Tampa-based Odyssey Marine Exploration is asking a three-judge panel of the federal appeals court in Atlanta to give it the rights to an estimated $500 million in silver coins and other artifacts salvaged about four years ago.

The federal judge in Tampa ruled in 2009 that Spain is the rightful owner of the treasure from a ship that's believed to be the navy frigate Nuestra Senora de las Mercedes y las Animas.

Odyssey counters that it is entitled to most of the loot because historical records show the vessel was on a commercial mission when it sank under fire in 1804.