Square Waves: The Beautiful But Deadly Ocean Pattern You Should Never Swim InIf you are at the beach and you see the ocean suddenly looks like a giant checkerboard or a chessboard, stay out of the water. What you are seeing is called square waves, also known as cross seas, and while they look amazing, they are one of the most dangerous things in the ocean.Square waves happen when two different wave systems collide.Normally, all waves move in one direction. But sometimes, a new wind starts blowing from a different angle, or a swell from a faraway storm arrives. When these two wave systems meet at a 90-degree angle, they crash into each other and form a perfect grid pattern on the surface. It looks like squares drawn on the water.From the shore or from a drone, it looks calm and beautiful. People want to take photos of it. But underneath that beautiful pattern, the water is chaos.The water is actually moving in two completely different directions at the same time. This creates powerful, unpredictable currents under the surface. The wave heights become uneven, and the water can pull you in multiple directions at once. You cannot predict where the next wave will come from.This is why square waves are so dangerous for everyone.For swimmers, surfers, and paddleboarders, it is almost impossible to keep your balance. For small boats and kayaks, the crossing motion can easily flip you over. Even the most experienced surfers and lifeguards stay out of the water when they see cross seas. The currents are much stronger than they look.What Should You Do If You See Them?If you are on the beach: Do NOT go in. Admire them from a safe distance and take a picture, but don’t swim. This is not the day for swimming.If you are already in the water: Get out calmly. Don’t panic and splash. Swim back to shore as soon as you see the grid pattern forming.If you are on a boat: Reduce your speed, wear your life jacket, and get back to shore if possible. Pay close attention to marine radio warnings.Always check the beach flags, listen to the lifeguards, and check the weather forecast before you go to the beach. If the beach has a red flag or the lifeguard says no swimming, please listen to them. They put those warnings there for a reason.Square waves are a perfect reminder that the ocean is beautiful but very powerful. Some of the most beautiful things in nature are also the most dangerous.If you see this checkerboard pattern on your next beach trip, enjoy the view, but stay on the sand.
