Every 20 years or so, the remains of a 50-foot shipwreck are exposed on a Maine beach in the wake of strong storms, only to be buried again by more harsh weather. It’s a mystery that has frustrated locals wanting to know more about the ghost ship. According to the CNN website, the ship was first spotted in 1958, then reappeared in 1978, 2007, 2013, and 2018. Some pieces of the ship were saved, and now the mystery has been cleared up.

A marine archaeologist sent pieces of the wreck to the Cornell University Tree-Ring Laboratory, where the timber was matched in a tree-ring index to a probable date of 1753. With that data, the archaeologist studied historical records and linked it to a sloop called Defiance, built in 1754 and wrecked near the Maine location in 1769. Defiance sailed out of Salem, Massachusetts, with a cargo of flour, pork, and other goods. Crewed by four men, the ship hit a fierce storm and was forced onto the beach. Although the sloop was a total loss, all four men survived.

The identification is significant because Defiance is one of the few examples of a pre-Revolutionary War ship built in New England. Scientists also hope to use the information to measure the impact of sea level rise and storm activity.