YARMOUTH, Mass. — The undersea explorer who discovered the Whydah Gally, the first authenticated pirate shipwreck in North America, believes he’s found where the ship’s legendary treasure lies after more than 30 years of poking around the murky waters off Cape Cod.

Barry Clifford tells the Associated Press his expedition recently located a large metallic mass that he’s convinced represents most if not all of the 400,000 coins and other riches believed to be contained on the ship.

“We think we might be at the end of the rainbow,” Clifford said in the recently opened Whydah Pirate Museum on Cape Cod, where many of the expedition’s finds are now showcased.

Maritime archaeologists and historians say they’re intrigued but remain skeptical, mostly because he’s been disproved on other finds.

“Barry Clifford’s many claims can be very exciting, if they can be verified with photographs or scientific proof,” said Paul Johnston, a curator at the Smithsonian’s National Museum of American History in Washington D.C. who specializes in shipwrecks. “Until then, it’s just talk.”