Locals are still reeling from the death of two children on a crowded Bournemouth beach last week.
12-year-old Sunna Khan and 17-year-old Joe Ebbess drowned. May 31 after they were reportedly blown off the sandbar while eight other campers got into trouble in the water.
Although the Dorset police have not yet figured out exactly what happened, the father of one of the survivors said his daughter was on the beach, having been swept away by a “rip current” near the pier.
Although not confirmed, Dorset Police said the investigation was “looking at all circumstances”, including weather, wind conditions and water conditions.
Here, MailOnline takes a look at the science behind the phenomenon and the best way to proceed if you ever find yourself in such a situation.
Ebb tides, more accurately known as rip currents and also simply “rips”, are fast-moving channels of water that move from the shore to the open sea. Instead of swimming back to shore, which can be dangerous, swim sideways to avoid the back current.
WHAT IS RIPTID?
Ebb tides, more accurately known as rip currents and also simply “rips”, are fast-moving channels of water that move from the shore to the open sea.
They can reach speeds of up to five miles per hour – faster than an Olympic swimmer – making them a major danger to all surfers.
The National Weather Service explains: “Rip currents form when waves break on a shoreline, accumulating water between the breaking waves and the beach.
“One of the ways this water returns to the sea is through the formation of a reverse current, a narrow stream of water moving rapidly away from the shore, often perpendicular to the coastline.”
Although the father of one of the survivors said that his daughter was swept away by a “rip wave”, a more accurate term for this kind of current on the beaches would simply be “rip wave”.
Gerd Masselink, professor of coastal geomorphology at the University of Plymouth, told MailOnline: “Rip currents are often referred to as low tides, which is a misnomer and we have been fighting for decades to get rid of the term, but to no avail. .’
Professor Masselink is involved in a research project specifically on the backflow at Bournemouth, which is common there, and its relationship to coastal facilities.
Bournemouth Beach is pictured here on June 2, two days after the death of two children. Dorset Police said the beach was “extremely crowded” at the time of the incident.
“They especially occur when the wind blows along the beach and the waves hit the shore at an angle,” he told MailOnline.
“This creates shore-parallel currents that veer seaward when they collide with shore-perpendicular coastal structures such as breakwaters and piers, resulting in a seaward flow towards the currents.”
Chris Brewster, retired San Diego Chief of Lifeguards, agreed that the term “ebb current” is “misleading” because “rip currents are not caused by tides.”
“It was an old belief that was debunked,” he told MailOnline.
“Typically, wherever there is a wharf, pier or other structure, as well as waves, rip currents form nearby.”
WHAT LOOK LIKE DISCONNECTING CURRENTS?
The reverse currents are visible from afar, so if you’re on a beach, it’s worth checking out the surf area before entering.
They are very similar to a road or a river running straight to the sea, a blue stripe among the roaring white waves.
Where there is a reverse current, there is a noticeable break in the waves, although this is best seen from a high vantage point, so lifeguards sit on tall, tower-like chairs.
ARE TEAR-OFF TURNS CAUSED BY BOATS?
Dorset Police issued a statement the day after the incident, stating that the man “who was on the water at the time” was arrested on suspicion of manslaughter, although he has since been released under investigation.
His release came when officers seized a cruise boat called The Dorset Belle, placing it under the guard of Poole Harbor, five miles from Bournemouth Pier, where it usually sails from.
Rip currents are very similar to a road or a river running straight to the sea, a blue stripe among roaring white waves.
It is not known whether the reverse current actually occurred last Wednesday and how it was connected to the Dorset Belle pleasure boat detained by the police.
“Insiders” speculated that the “sudden rupture” contributed to their demise and could have been caused by the boat.
The source said Sun: “They were on the sandbank east of the pier when the Dorset Belle docked at the pier.
“It created a whirlpool that swamped everyone on the sandbar and basically forced them further out to sea.”
However, according to Professor Masselink, boats do not cause tides to ebb and flow; rather, they form as a result of the natural interaction of water.
Dr Sergio Maldonado, lecturer in hydraulics at the University of Southampton, agreed, telling MailOnline: “Boats can certainly disturb local flow depending on their size and speed, but I can’t think of any mechanism by which they could cause a steady , strong current.’
The Dorset Police have seized the cruise boat The Dorset Belle and put it under guard at Poole Harbour.
WHY DANGEROUS LEATHER CURRENT?
Rip currents can carry even the strongest swimmer out to sea and cause loss of life as those caught in them try to fight back.
Once caught in a reverse current, panicked swimmers often try to resist it by swimming back to shore, at the risk of drowning due to fatigue.
“The danger arises when a misguided swimmer uses an inadequate strategy to avoid a break, such as directly fighting the current,” said Dr Sergio Maldonado, an environmental mechanics expert at the University of Southampton.
“This can lead to fatigue, panic and, in some cases, drowning.
“Swimming straight up against a break can require several times more energy from the swimmer than other strategies recommended by lifeguards.”
Rip currents are common on Bormouth Beach (pictured). They especially occur when the wind blows along the beach and the waves hit the shore at an angle.
According to the American Boating Association, rip currents are usually strongest about a foot from the bottom of the water.
As a result, this can cause someone’s legs to be kicked out from under them, making it feel like something underwater is being pulled from below.
HOW TO SURVIVE THE CURRENT
The best way to escape the reverse current is to swim parallel to the shore, not towards it, and most importantly, to remain calm.
Swimming back to shore simply means that you are swimming into a gap that will tire you out and possibly drown you.
Alternatively, by going with the flow, you can return to a sandbank, a deposit of sand that forms shallow water in the sea.
The National Oceanic and Atmospheric Administration has this advice if you ever find yourself in a reverse current: “Don’t fight it. Swim parallel to the shore and swim back to land at an angle.
The best way to avoid breaks altogether is to choose a beach protected by lifeguards and always swim between the red and yellow flags, which are marked depending on where it is safer to swim in the current conditions.