Updated

A recent dive at the site of the only authenticated pirate ship wreck in U.S. waters has signaled the possible location of even greater treasures.

Already 200,000 artifacts, from gold to guns, have been documented from the site of the Whydah, which sank during a ferocious storm off Cape Cod in 1717.

Undersea explorer Barry Clifford located the wreck site in 1984. But he only recently learned that 400,000 coins were stolen from two boats the Whydah raided in the weeks before it sank.

The final dive Sept. 1 at the end of a three-day trip found an area heavy with metal, including what appears to be coins, some stacked.

Now, Clifford plans to return to the site as soon as weather permits.