If you see square waves forming in the ocean, get out of the water immediately

Embracing the joys of summer often involves taking a refreshing dip in the water, and many flock to beaches during this season to indulge in this favorite pastime. However, amidst the sun and surf, it’s crucial to remain attuned to our senses of touch and scent.

A single misstep can lead to perilous consequences. While rip currents and shifting tides are well-known hazards, there’s a lesser-known danger that lurks in the waters, the square wave.

Though seemingly enchanting, the square wave, also referred to as a cross sea, poses a significant threat in oceans and other bodies of water. This phenomenon occurs when two or more waves converge, creating a distinctive square or checkerboard pattern.

As explained by the European Space Agency (ESA) in 2010, cross seas materialize when a windsea and a swell, or two distinct swell systems, coexist. A 2004 study noted a high incidence of ship accidents in crossing sea states, emphasizing the inherent dangers.

Cross seas give rise to swells that can reach heights of up to ten feet, accompanied by intricate wind patterns. Navigating such conditions becomes challenging for both boats and swimmers.

Encountering square waves is rare, but if identified, it is imperative to avoid using boats or swimming in these perilous waters. Instead, it is advisable to relish the beach, biding time until weather conditions improve for safe outdoor activities.

While visually stunning, square waves can manifest in specific locations where two seas converge at a land’s tip, creating a refracting pattern that resembles a checkerboard. The French Island of Re, off the coast of La Rochelle, and Cape Reinga in New Zealand, where the Pacific and Tasman Seas meet, are notable places to witness these mesmerizing waves.

Despite their allure, caution is paramount. The popularity of these locations as tourist attractions underscores the fascination with square waves, drawing thousands to witness the spectacle from a safe distance.

The phenomenon is not confined to exotic locales, as shallow waters, such as those off the Isle of Rhe and Tel Aviv, Israel, also experience the intriguing interplay of opposing surges, attributed to the Kadomstev-Petviashvili equation.

In the realm of ocean dynamics, square waves serve as a captivating yet potentially perilous manifestation, demonstrating the complex interactions between various weather systems.