Because of how active the coast of Maine is, it should not be a big surprise that several oddities have been discovered off the coast of Maine. Old Sow, for example. The Old Sow Whirlpool in MaineAccording to the Old Sow website (yes, the whirlpool has its own website), Old Sow is the largest tidal whirlpool in the Western Hemisphere. Old Sow is created by huge amounts of seawater rushing through deep underwater channels, around underwater rock formations, and through several strong currents and countercurrents. As for the name "Old Sow," one theory is that the whirlpool makes a sound similar to a pig when it is churning.