Neuron Expedition — exploring the Hranice Abyss, 2015

What are water samples from a depth of 384 metres, from the world's deepest flooded cave, like? The hydrogeologist Helena Vysoká and a team of cave divers explored the last blank spot on the map of the Czech Republic.

The Neuron Expedition ended successfully — and straight away with a world discovery! Helena Vysoká's team proved that the Hranice Abyss is the deepest flooded cave in the world!

The subject of the 2015 Neuron Expedition: humanity has known the Hranice Abyss for centuries and diving exploration has been going on there for decades, but findings concerning the water in the abyss itself had never been processed comprehensively. No comprehensive hydrogeological research aimed directly at the Hranice Abyss had taken place there, and the results of the partial studies carried out so far had mostly not been published — indeed, in many cases they cannot even be traced. One of the aims of the project was therefore also to provide a fuller summary of the findings concerning the water in the Hranice Abyss. The Neuron Expedition that carried out the scientific research of the abyss was led by the hydrogeologist Helena Vysoká, who received a total of CZK 250,000 from the Neuron Endowment Fund for the project in 2015. It was also established that, according to the most recent measurement in 2016, the Hranice Abyss is 404 metres deep. It is therefore the deepest flooded cave in the world! The depth of the Hranice Abyss was measured, with the support of the National Geographic Society, by a team of speleologists that included the experienced diver Krzysztof Starnawski.

What they wrote about the Neuron Expedition:

Confirmed: the world's deepest flooded abyss lies in the Czech Republic (Web Cestovatelů, 5 October 2016)
The Hranice Abyss has the world's deepest underwater cave. Scientists measured 404 metres (Czech Television, 30 September 2016)
Confirmed: the world's deepest flooded abyss lies in the Czech Republic (nfneuron.cz, 30 September 2016)
The Hranice Abyss is at the limit of human endurance, says an Ostrava diver (iDnes.cz, 16 April 2016)
The Hranice Abyss is only eight metres short of the record. Divers are still exploring its depth (iHNed.cz, 14 September 2015)
The Neuron Expedition calls for a journey that will push back the boundaries of human knowledge (Věda pro život, 11 September 2015)
The Hranice Abyss. A completely new world. (Vesmír, 10 August 2015)
Research into the Hranice Abyss is to reveal its depth and the composition of its water (Ekolist.cz, 27 July 2015)
Is the world's deepest flooded cave in the Czech Republic? The research is beginning (EuroZprávy.cz, 25 July 2015)
A scientific challenge in the depths (Přírodovědci.cz, June 2015)
Is the Hranice Abyss the deepest in the world? The next dive is aiming for 400 metres (iDnes.cz, 21 May 2015)
The last blank spot on the map of the Czech Republic is the Hranice Abyss (Rádio Zet, 28 April 2015)
Lucie Výborná, patron of the Neuron Expedition, on the Jan Kraus Show (Prima, 4 March 2015)