CHATHAM, MASS. >> A rare sighting of a killer whale has been made off Cape Cod.

The orca was spotted Monday by 60-year-old charter fishing boat captain Bruce Peters about 13 miles northeast Chatham.

A spokesman for the New England Aquarium says researchers conferred with a marine mammal researcher in Canada and confirmed that it was a male orca named Old Thom.

The roughly 30-feet-long, eight-ton whale had been spotted by researchers in 2014 and 2015 off Nova Scotia and in the Bay of Fundy.