In an effort to draw attention to the environmental deterioration of the Dead Sea, on Tuesday a multinational group of 25 swimmers swam seven hours through the thick, salty, soupy waters of Israel’s legendary lake in the first-ever international Dead Sea Swim Challenge.

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As the lowest point on earth, 423 meters (1,388 feet) below sea level, and the deepest hyper-saline lake in the world, the Dead Sea is a natural and historical wonder. Tourists flock to the Dead Sea to float on the water thanks to the lake’s high salt concentration. It also attracts people from around the world who believe the water’s high mineral content is beneficial for skin conditions.

Tragically, however, the Dead Sea is disappearing before our very eyes. Over the last 30 years, the Dead Sea’s water level has dropped by more than 25 meters (80 feet). Environmentalists blame this phenomenon on unsustainable water management and over-exploitation of the lake’s minerals. Due to heavy industrialization, the Dead Sea’s southern basin, disconnected from the shrinking northern side, has seen flooding in recent years.

In the early morning hours of Tuesday, the 25 swimmers boarded boats and sailed from Israel’s Ein Gedi to Jordan’s Wadi Mujib, which was the swim’s starting point. Then, wearing special protective masks and snorkels to shield them from the briny water, which is painful to the eyes and can be deadly to ingest, the swimmers swam for seven hours through the salty waters in a 17-kilometer (11-mile) swim from Jordan to Israel.

Although floating on the Dead Sea is common, swimming in it is both unusual and potentially dangerous. The swimmers were therefore accompanied by support vessels with medical equipment and food. Despite the very difficult conditions, only three swimmers failed to finish — two who suffered from dehydration and another who complained of chills. Four swimmers took breaks on the medical boat, including Yussuf Matari, a 61 year-old lifeguard, who was treated with an IV on the medical boat before resuming his swim.

The group included local swimmers from Israel and others who came from as far away as New Zealand, South Africa and Denmark. “This is really important because it’s disappearing fast,” British long-distance swimmer Jackie Cobell told the AP, calling the Dead Sea swim “historic and iconic.”

Those who reached the shore first patiently waited, so all the swimmers could finish the race together while loudspeakers blared the iconic hit by British rock band Queen, “We are the Champions.”

Raising awareness for a historic, but shrinking, body of water

“We’re here for the first ever Dead Sea swim challenge with 25 swimmers who come from all over the world to send out a clear message to save the Dead Sea, which is shrinking today at an alarming rate,” Mira Edelstein, a spokesperson for the environmental group EcoPeace, one of the swim’s organizers, told the AP. Jean Craven, the founder of Madswimmer, a South African charity that participates in open-water swims around the world to raise money for children’s causes added: “This was a challenge, not a race.”

Pictures and Video: DeadSeaSwim.com