The Atlantic White Shark Conservancy confirmed it was a sighting of Old Thom, the only orca regularly seen in North Atlantic waters. The New England Aquarium says the large male killer whale, recognizable by an indent on his tall dorsal fin, is known to swim alone or with dolphins even though orcas typically travel in pods.

An orca was recently spotted swimming with a pod of dolphins off the coast of Massachusetts in a rare killer whale encounter caught on video. Donna Piraino, of the charter Go Girl Fish, was out fishing for tuna in the Stellwagen Bank National Marine Sanctuary off Gloucester this past weekend when her vessel came upon the whale.