People warned to get out of the ocean immediately if they spot this bizarre detail in the water

The ocean surface is a reflection of what’s embroiling underneath and can often be as eerie as the darker depths. Time spent in the sea is undeniably a time worth cherishing, but this blissful moment may soon turn into a daytime nightmare if a person is unaware of their surroundings. While sea waves are barely threatening on most days, life-saving experts advise people to hop out of the water as soon as they spot bizarre quadrilateral shapes forming on the surface, called square waves, per Surfer Today. This strange weather anomaly is a threat to swimmers, surfers, and even boats as it can quickly suck them up within seconds. 

Square waves are a rare phenomenon formed when two opposing swells collide at exactly right angles to create a grid-like pattern on the ocean surface, per the source. The square-shaped ripples, as they appear, are extremely risky because it is associated with strong and localized rip tides. Also known as cross sea or grid waves, the phenomenon challenges even the best of swimmers and most experienced sailors with waves reaching heights as tall as 10 feet (3 meters). Therefore, fleeing out of the waters is the only viable way to possibly escape square waves. 

"If caught in a square wave, the most important thing to do is get out of the water immediately, as they are extremely dangerous,” Mathew Giachetti of the United States Lifesaving Association (USLA) told Islands.com, adding, “They can pull you in multiple directions at once, making escape challenging.” When in crisis, if a person is caught amid the cross sea, he advised, staying calm and trying to float on your back. To escape the wave’s strong force, it is best to swim parallel toward the shore and reach the land sooner. “If you can't reach the shore quickly, signal for help,” Gachietti emphasized. According to the expert, the square waves are impossible to predict and might not be visible when in water. They may seem superficial but their elusiveness is what makes it more threatening. 

Square waves are typically viewed from higher angles, like the top of cliffs or lighthouses, and are a fascinating sight that invites tourists to such spots, mostly coastal areas like Isle of Ré in France, New Zealand’s Whangamata Beach, Anna Maria Island, Florida and in regions in the South Pacific and the Atlantic Ocean. Earlier, square waves were dreaded for causing severe damage to vessels and shipwrecks from 1995 to 1999, the European Space Agency (ESA) reported. A study from Proceedings of the 13th International Offshore and Polar Engineering Conference also attested to this fact and investigated its contribution to a number of maritime accidents in 2003. 

Believe it or not, ocean currents are integral to predicting and assessing weather conditions in addition to estimating the state of the vast water bodies. According to NOAA, they are known to cause warmer climates in Western Europe while sustaining marine life in Antarctic waters. However, any disruption to ocean currents may have a larger impact on the world, even though it may not seem to have a direct link. Irregularity in ocean currents is said to have caused the mass extinction of 95% of all marine life about 250 million years ago.