Travelling down Georgian Bay today we spotted a small version of the phenomena called crossed sea. This is a pattern of waves forming a series of squares. Apparently there are some quite famous location where they occur: Isle of Rhé off the coast of France and the beaches of Tel Aviv. The waves are the result of two different weather/wind systems that result in waves coming from two different directions.
High school physics offers an explanation using wave theory and patterns of constructive and destructive interference. Today’s waves were not a big deal as they were small but larger ones can be quite dangerous for vessels. They are capable of tipping over large boats and are suspects in many historical shipwrecks.
Moon Dance IV 