Divers had planned to recover the second-largest artifact on what's believed to be the Queen Anne's Revenge but discovered it was too well-attached to other items in the ballast pile, said project manager Mark Wilde-Ramsing. Instead, they pulled up another anchor that is the third-largest artifact and likely was the typical anchor for the ship.
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The anchor is 11 feet, 4 inches long with arms that are 7 feet, 7 inches across. It was covered with concretion -- a mixture of shells, sand and other debris attracted by the leaching wrought iron -- and a few sea squirts. Its weight was estimated at 2,500 pounds to 3,000 pounds.
The anchor's size is typical for a ship the size of the Queen Anne's Revenge, while the two other anchors probably were used in emergencies, such as storms, Wilde-Ramsing said.
http://www.latimes.com/news/la-naw-blackbeard-anchor-20110527,0,6892753.story