An American company is in the process of determining the value of a haul of sunken treasure, thought to be the biggest ever discovered. Odyssey Marine Exploration says it is examining more than half-a-million coins from the shipwreck as part of a find that could net it around half a billion dollars. The bounty has sparked public interest in the controversial business of treasure hunting. Steve Mort reports for VOA from the Florida city of Tampa where Odyssey Marine Exploration is based.

Crates of coins from the shipwreck being unloaded from a cargo airplane

Odyssey won't reveal the identity of the ship, or even when it sank, to avoid giving clues to other treasure hunters. Odyssey will only say it went down in international waters.

In the crates are 17 tons of silver and gold coins and other valuables arriving in the U.S., destined for a secret location.

Mark Gordon

Those crates could hold about half a billion dollars.  In the U.S., a big media splash about the "Black Swan" hoard has triggered a new fascination in pirate ships and treasure.

Eugene Holseybrook came to see a company exhibit in Tampa.  "I like it. I've actually visited some of the exhibits and find it very interesting,"  he said.

Odyssey estimates there are some three million shipwrecks worldwide. The company combs the seabed using a special underwater vessel: operating it costs $35,000 a day.

If treasure is found, the company determines if anyone may have a claim to it -- unlikely in the case of a pirate-ship -- then petitions a U.S. court to get ownership.

Odyssey's Vice President of Attractions, Roger Kurz, says once the court rules in favor, the bounty can be sold.  "We send our Zeus, our remotely operated vehicle, down to pick up more artifacts, then we put them into the conservation phase," says Kurz. "And if we find one, or two, or three items then we would put them in the Odyssey collection which we keep forever. If we find more than that then we put them for sale so that guests throughout the world can retain a piece of history."

Odyssey is the only publicly traded treasure-hunting company in the U.S., but the business is unpredictable. It reported a net loss of $3.8 million in the first quarter of 2007.

A coin from a shipwreck expedition

Critics, such as the Institute of Field Archaeologists, accuse private companies like Odyssey of "ransacking" shipwrecks for profit. And Odyssey is in a legal wrangle with the Spanish government over the Black Swan treasure. Spain says it might be one of their galleons that went down in its territorial waters.

But Odyssey says it will press on with its work - and has even teamed up with the Walt Disney Corporation to cater to the public appetite for sunken treasure.