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It's been a long time since most of us were able to think about going on holiday and dipping our toes in the ocean. But here's some useful advice - if you're at the beach and spot 'square waves' in the water, it's best that you get yourself and your loved ones back on dry land immediately.
This phenomenon is called 'cross seas' - or alternatively, 'squared sea' or even 'squared waves' -and can be very dangerous.
In simple terms, the squared patterns occur when two separate weather conditions collide while moving in different directions - resulting in a scenario where you'll find it difficult to get yourself out of the sea with two sets of waves smashing into you simultaneously.
According to a 2006 study, this sea state is quite common, with a large percentage of ship accidents occurring due to weather changes.
The topic was the subject of discussion over on Reddit, with one user in particular seeming to have decent grasp on the topic.
They wrote: "A cross sea looks beautiful from afar but is actually very dangerous.
"The pattern occurs when two wave systems cross while traveling at slanting angles to each other.
"The waves from the older weather system continue on until they dissipate, and the ocean becomes a swirling, dangerous place for swimmers and boats."
Another person explained: "These are long-period swells caused by weather systems actually far apart from each other.
"The swells generated by those systems were at this angle to each other.
"They then travel sometimes long distances and can eventually collide like this."
A third added: "They are actually quite dangerous," while another seemed to be taking things a bit less seriously when dubbing them the 'most uncool and unhip waves in the ocean'.
Of course, the ocean sees plenty of bizarre and terrifying phenomena - back in December, footage was captured showing a huge multiple-vortex waterspout, swirling over the surface of the sea.
The incredible natural phenomenon was seen by Gilad Raz in Caesarea, Israel, on 17 December and images show the waterspout swirling over the ocean, edging its way towards the coast.
The incredible footage was captured by Frank LeDay, who shot the waterspouts far out at sea. He wrote: "Wow!! Ever see six waterspouts at once?"
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