Explorers Discover World's Deepest Known Underwater Cave in Czech Republic

The Hranicka Abyss is at least 1,325 feet deep, and likely goes down further.

October 5, 2016, 6:27 PM

— -- A team of explorers believe they have discovered the deepest known underwater cavern the world in eastern Czech Republic.

The flooded fissure, which is at least 1,325 feet deep, is known as the Hranice Abyss, The Associated Press reported.

Polish explorer Krzysztof Starnawski, who led the team, told the AP that divers have explored the underwater cavern's upper parts for decades.

PHOTO: This map made available to The Associated Press by Polish explorer Krzysztof Starnawski on Sept. 30, 2016, shows a cross-section of the flooded Hranicka Propast, or Hranice Abyss, in the Czech Republic.
This map made available to The Associated Press by Polish explorer Krzysztof Starnawski on Sept. 30, 2016, shows a cross-section of the flooded Hranicka Propast, or Hranice Abyss, in the Czech Republic that Starnawski's Czech and Polish team recently revealed to be the world's deepest known flooded cave.

But last Tuesday, Sept. 27, Starnawski said he and his team went down into the abyss where no one else had ever gone before.

Starnawski, 48, dived more than 650 feet down the cavern to a narrow slot before sending a remotely operated robot to go down, the AP reported.

PHOTO: In this photo taken Sept. 27, 2016, in the flooded Hranicka Propast, or Hranice Abyss, in the Czech Republic, shows the screen of a remotely-operate underwater robot, or ROV, indicating it has reached the depth of 1322.18 feet.
In this photo taken Sept. 27, 2016, in the flooded Hranicka Propast, or Hranice Abyss, in the Czech Republic, shows the screen of a remotely-operate underwater robot, or ROV, indicating it has reached the depth of 1322.18 feet in the cave, revealing it to be the world's deepest known flooded limestone sinkhole, during an expedition led by Polish explorer Krzysztof Starnawski.

The ROV was able to go down another 650 or so feet, or the length of its cord, but still did not hit the bottom, Starnawski told the AP.

Still, the discovery officially made Hranice Abyss the world's deepest known underwater cavity, Starnawski said. He added that the underwater cave beat the previous record-holder, a flooded sinkhole in Italy called Pozzo del Merro, by at least 39 feet.

PHOTO: Czech Republic Polish explorer Krzysztof Starnawski, left, and Bartlomiej Grynda, right, are reading images from a remotely-operated underwater robot, or ROV, that went to the record depth of 1,325 feet, on Sept. 27, 2016.
Czech Republic Polish explorer Krzysztof Starnawski, left, and Bartlomiej Grynda, right, are reading images from a remotely-operated underwater robot, or ROV, that went to the record depth of 1,325 feet, on Sept. 27, 2016.

Starnawski told the AP that diving in the cave was a challenge because of its muddy areas and the water's mineral composition, which can damage equipment and harm exposed skin.

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

PHOTO: In this underwater photo taken Sept. 27, 2016, in the flooded Hranicka Propast, or Hranice Abyss, in the Czech Republic, a remotely-operated underwater robot, or ROV, is exploring for the cave's bottom, which it did not find.
In this underwater photo taken Sept. 27, 2016, in the flooded Hranicka Propast, or Hranice Abyss, in the Czech Republic, a remotely-operated underwater robot, or ROV, is exploring for the cave's bottom, which it did not find, despite descending to the depth of 1,325 feet.

A cross-section map Starnawski made of the cave ends with question marks in an unexplored area where he believes it goes deeper.

National Geographic, which first reported the discovery, covered some of the expedition's cost, the AP reported.

PHOTO: In this underwater photo taken Aug. 15, 2015 in the flooded Hranicka Propast, or Hranice Abyss, in the Czech Republic, Polish explorer Slawomir Packo is exploring the limestone abyss and preparing for deeper exploration.
In this underwater photo taken Aug. 15, 2015 in the flooded Hranicka Propast, or Hranice Abyss, in the Czech Republic, Polish explorer Slawomir Packo is exploring the limestone abyss and preparing for deeper exploration with the use of a remotely-operated underwater robot, or ROV.