This rare wave pattern occurs when two swells coming from different directions meet and form squares on top of the water, often resembling a checkerboard or grid. It's called a cross sea because ...

Another type of dangerous and deadly wave is the square wave pattern. When the water makes a grid shape, it's referred to as cross-sea waves, and if you see them, get back on shore immediately.

While you may know a thing or two about traditional rip currents and changing tides, you might not be aware of the dangers of square waves, otherwise known as a cross sea. Yes, square waves are a ...