Archaeologist Marie Kesten Zahn displays a silver coin recovered from the wreckage of the Whydah Gally.

Archaeologist Marie Kesten Zahn works to remove silver coins from a concretion recovered from the wreckage of the pirate ship Whydah Gally at the Whydah Pirate Museum, in Yarmouth, Mass. Steven Senne/Associated Press

Archaeologist Chris Macort holds a bronze wheel wax seal recovered from the wreckage of the pirate ship Whydah Gally.

A museum visitor walks by a display of a bell once belonging to the pirate ship Whydah Gally at the Whydah Pirate Museum, in Yarmouth, Mass.

A full-size replica of the hull of the pirate ship Whydah Gally is surrounded by numerous artifacts from the ship at the Whydah Pirate Museum, in Yarmouth, Mass.

Undersea explorer Barry Clifford stands next to a display case containing silver coins recovered from the wreckage of the pirate ship Whydah Gally. Clifford, who discovered the Whydah Gally, the first authenticated pirate shipwreck in U.S. waters, says he’s finally found where the ship’s vaunted treasure lies after more than 30 years of poking around the murky waters off Cape Cod.