Explorers find world's deepest underwater cave

With a depth of 404 meters (1,325 feet), a flooded limestone formation in the Czech Republic is now the world's deepest underwater cave, explorers announced on Friday. The data beats out Italy's Pozzo del Merro flooded sinkhole, which is 392 meters deep.

"We wanted to beat the Italian record. We succeeded and now we have the magic number of 404 meters," Miroslav Lukas of the Czech Speleological Society told the AFP news agency.

The cave, called the Hranicka Propast, or Hranice Abyss, was uncovered by a Polish-Czech team in an eastern part of the Czech Republic. Divers have been exploring the underwater cave's murky depths for decades, but its depth had remained unknown.

Krzysztof Starnawski, a Polish explorer who led the team, scuba dived to a narrow opening 200 meters down on Tuesday. He then positioned a remotely operated underwater robot to take measurements further down, he told the Associated Press.

Even with the help of a robot and its long cord, the explorers were still unable to reach the cave's bottom. The robot ran out of cord at 404 meters.

"It was as deep as its rope could go, but the bottom was still nowhere in sight," the Czech Speleological Society said in a statement. The Hranice Abyss is likely much deeper, the explorers added.

Diving in the flooded Czech cave is difficult due to muddy areas and a chilly water temperature of 15 degrees Celsius (59 degrees Fahrenheit). Additionally, water in the limestone cave has a mineral composition that damages equipment and exposed skin, Starnawski told AP.

"But that is the only price to be paid for this discovery, and it was worth paying," he said.

The Polish explorer plans to dive down again to 200 meters on Saturday in order to bring the robot back to the surface.

The project was co-financed by the National Geographic Society, which broke the story late on Thursday night.

rs/sms (AP, AFP)