Old Sow whirlpool

Old Sow (Mocinikosk, in Maliseet-Passamaquoddy) is the largest tidal whirlpool in the Western Hemisphere, located off the southwestern shore of Deer Island, New Brunswick, Canada, and off the northeast shore of Moose Island, the principal island of Eastport, Maine. It is considered most visible and dangerous three hours after low tide.

The name has been in use since at least 1935.