Old Sow Whirlpool

Old Sow forms between Deer Island and Eastport, Maine, where the Fundy tide pushes an enormous volume of water past an underwater mountain and through a channel of uneven depth; the result is the largest tidal whirlpool in the western hemisphere, reaching around seventy-five metres across with a visible funnel that can open several metres deep. Smaller vortices around it are known as piglets. It is strongest about three hours before high tide and largely absent at other times. Deer Island Point Park gives a land view, and boat operators run to it in settled conditions.

History

The Maliseet-Passamaquoddy name is Mocinikosk, and the English name Old Sow has been in use since at least 1935. In the 1930s the failed Passamaquoddy tidal power project built a series of dikes linking Moose Island at Eastport to Carlow Island and Pleasant Point and Treat Island to Dudley Island, and the change in the currents is said to have made the whirlpool's funnel less predictable; in 1997 an aerial photograph measured the area in which the whirlpools form at about 250 feet across (Wikipedia, Old Sow whirlpool).

What you'll find

• The main vortex - a funnel that can open several metres deep.
• The piglets - smaller whirlpools and boils around the main one.
• The tidal drive - the Fundy range forcing water through a constricted channel.
• The land viewpoint - Deer Island Point Park above the water.

When to go

June to September, and specifically about three hours before high tide, which is the only time it forms properly; at other states of tide there is little to see. Boat tours run in settled weather.

Before you go

The whirlpool is only present for part of each tidal cycle and its strength varies with the moon. It rarely matches dramatic photographs. Boats keep a distance for safety.

Nearby

Campobello lies south; St. Andrews is north.

Key facts