Old Sow Whirlpool

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.