I didn't mind so much gettin caught in it. What I resented was havin to row uphill to get out!

What Is Old Sow?

Old Sow is the largest natural whirlpool in the Western Hemisphere, and is one of five significant whirlpools worldwide. While most people envision a single, huge gyre when they think of a whirlpool, Old Sow infrequently and unpredictably  due, in part, to the nearby tidal dams that were built during the failed tidal power project of the 1930s  forms a large funnel in the water; however, it does frequently form a huge area of many kinds of facinating turbulence. The roiling comes in the forms of fast currents and eddies, standing walls of water, "boils," "spouts," "troughs" or "dishes," "holes," and numerous medium-size and small gyres. A rare major funnel is more apt to appear when tides are running especially high (as during spring tide), coinciding with strong winds.

Where Is It?

Old Sows sty is Western Passage of Passamaquoddy Bay, in the Bay of Fundy. Western Passage is just west of Deer Island, New Brunswick, Canada, northeast of the island city of Eastport, Maine, USA, and east of Sipayik (Pleasant Point Passamaquoddy Reservation) and Perry on the Maine mainland. Western Passage connects the large open portion of Passamaquoddy Bay to its southern reaches.

Old Sow wanders around a bit, when active. On the flood tide, it occurs just to the west and north of the southern tip of Deer Island. It is near the international boundary, but is more on the New Brunswick side of the line. On the ebb tide, Old Sow wanders futher to the south, and is generally less apparent, although there is still considerable turbulence. Some mariners have reported that sometimes Old Sow is even more active on the outgoing tide.

Just How Big Is Old Sow?

How does one measure a whirlpool? The broad area of disorderly water is vast, running from near Clam Cove, Deer Island, to south of the international bridge between Campobello Island, NB, and Lubec, ME, a distance of around 7 miles / 11 kilometres, and to the northeast, between Deer Island and Indian Island (just to the south of Deer Island); however, Old Sow itself  the largest vortex and its compatriots  is confined to an area that is much smaller.

In 1997 the Old Sow Whirlpool Survivors Association President took an aerial photograph of the whirlpool. Using the diameter of the navigation beacon tower at the southern end of Deer Island as a reference, he extrapolated that the smaller, but most active of the two large vortexes that were present at that time was approximately 76 metres / 250 feet in diameter!

For more technical information about Old Sow, visit our Data page.

What Causes Old Sow?

Old Sow is tidal, and is the result of tremendous amounts of sea water rushing into a confined passageway (Western Passage of Passamaquoddy Bay), between Deer Island and Indian Island, then making a right-angle turn to the north around the southern tip of Deer Island, through a nearly 400-foot / 122-metre deep trench, around an underwater mountain that is around 119 feet / 36 metres below the waters surface, and then into another trench of over 350 feet / 107 metres deep. Additional significant current comes from between Campobello Island and Indian Island, turning northward, and then joining the previously described current. Undersea ledges and tidal waters coming north via Friar Roads, between Campobello Island and Moose Island, Eastport, contribute to Old Sows activity. There are also countercurrents coming south from the St. Croix and the Magaguadavic Rivers through Passamaquoddy Bay. There are numerous currents and counter currents which affect the activity of Old Sow. Tidal surges that accompany storms, along with strong winds, can contribute to Old Sows activity.

Why Is It Called "Old Sow"?

The name "Old Sow," some say, is due to a pig-like noise that the whirlpool makes when it is really churning. This explanation may be due to ancient folklore regarding "pigs of the sea" (porpoises), or may simply be a myth resulting from the whirlpool's current name. Old Sow does, however, make considerable noise when churning.

A more likely basis for the name, though, is corruption of the word "sough" (correctly pronounced "suff" or "so"), which has a couple of meanings: (1) a sucking noise, (2) a type of drain. Either of these definitions would apply to the whirlpool in question. People unfamiliar with the pronounciation of the written word "sough" might have assume that the pronunciation should be "sow," since the word’s ending is identical to many other words with an "ow"-sound ending, such as "plough" (pronounced "plow" and having the same meaning as "plow").

Viewing Old Sow and Other Local Whirlpools

Boat charters and excursions based out of, Campobello Island, Deer Island, Eastport, and Lubec will sail through Old Sow, upon request. For those willing to take the risk (generally safe in a motor-powered boat operated by a qualified captian), the Old Sow Whirlpool Survivors Association makes Survival Certificates available to those who pass through the whirlpool and survive!

Old Sow area starts to roil about 3 hours before high water (high tide), and continues for a couple of hours. Even then, when activity has diminished considerably, strange troughs in the water are sometimes observed.

Deer Island

The best on-land observations of Old Sow are from Deer Point in the Deer Island Campground, near the ferry landing at the south end of the island.

Moose Island (Eastports principle island)

Turbulent activity can be vaguely observed from the north end of Water Street or the east end of Clark Street on Moose Island in Eastport, although some excellent sightings have been reported from near this location during some of Old Sows infrequent, unpredictable extreme activity. From North Water Street, and during mid-tide, medium-size whirlpools can frequently be observed peeling off the north end of Dog Island.

East Coast Ferries, Ltd.

The seasonal ferries (Deer Island  Campobello Island / Deer Island  Eastport) that operate out of Deer Islands southern tip pass close enough to Old Sow to see considerable activity close-up.

Many other small and medium size whirlpools, as well as other tidal oddities, can be seen in the area  Cobscook Reversing Falls at Pembroke Reversing Falls Park, under the Roosevelt Memorial International Bridge at the Campobello-Lubec border crossing, at the northern end of Indian Island (south of Deer Island; however, this whirlpool can be seen well only by boat or plane), and at various other locations in the Quoddy Loop area.

Other Tidal Oddities

Other unusual tidal phenomena found in the area include thunder holes, tidal bores, reversing falls, inexplicable cross-currents, and standing waves. Even kelp passing edgewise over Cobscook Reversing Falls  with just a little imagination  can appear to be the finned spine of a seaserpent!