What goes through the mind of a person who has just broken the world record for cave diving? French speleologist and explorer Frédéric Swierczynski took seven hours to reach a depth of 308 metres in the Font Estramar, a labyrinth-like underground river in the south of France.
"I think I'm lucky to be among the last explorers. It’s quite wonderful to have gone to a territory that has never been seen," he told local news site Actu Perpignan a few days after his exploit in November 2023.
"At Font Estramar, I remember seeing these marks on the ground, traces of ancient landslides, all these minerals which have been frozen for millions of years. It's still pretty crazy. It’s been my passion since I was 18."
Swierczynski – who has spent two decades exploring the Font Estramar, near Perpignan in the Pyrénées-Orientales – broke the record set by Xavier Méniscus in 2019 at a depth of 286 metres.
He didn't set out with the objective of breaking the record; he just knew he wanted to push his own limits and go beyond his personal best of minus 260 metres at the Font Estramar.
"I wanted to continue in the minus 270-metre zone and get comfortable with my brand new equipment configuration. The idea was to test this in a real situation."
Lengthy preparation
Everything was prepared months in advance in a workshop near Marseille, where Swierczynski is based.
To avoid suffering from "the bends" and other side effects brought on by such depth, Swierczynski had to come up with a precise mixture of oxygen and helium. The equipment, including two battery-operated scooters and recycling canisters, was tested in the Mediterranean Sea. In total, his equipement weighed around 100 kilogrammes.
Swierczynski only realised he had broken the record on his way back, as he made the necessary safety stops and glanced at his instruments.
"Everything happens in relation to feeling, to sensations. It was the right time, I felt very well physically," he said.
Font Estramar presented "perfect weather conditions" at the time of the dive, Swierczynski added. It was very similar to one of his favourite spots called La Mescla, in the Alpes-Maritimes area, where he'd been training.
For the November dive, Swierczynski was accompanied by a group of 10 experts.
"These are people who are part of the medical field, who know everything related to decompression, who have already followed old world records, not only on Font Estramar but also at sea," he said.
Despite a public ban on diving, Font Estramar's deep watery caves regularly attract adventurers. In 10 years at least five divers have died there – the most recent fatality in July 2023.
Majestic scenery
Swierczynski described what he saw at minus 308 metres as "really majestic".
"The deeper you go, the lighter the rock. At the end of the dive, I saw a fairly large cavern of about 20x15 metres.
"There was a bit of everything: there were very narrow passages as well as very high passages. It’s quite impressive."
Despite the great risks involved, Swierczynski can't help being attracted to this kind of challenge.
"I think that the dangers are the same as those of everyday life. The problem is that if you feel unwell and fall on the sidewalk, it’s not always serious. If you feel unwell in the water, you won't come back from it."
But it's not just about breaking records. Swierczynski is keen to share his insights with scientists and provide clues for how the environment is evolving both here in France and abroad.
His most recent projects have taken him cave diving in Harasib, Namibia, while in 2019 he set a world record for altitude diving at Lac Ojos del Salado, in Argentina, at 5,870 metres.
At 50, Swierczynski has no intention of stopping. In fact, he's hoping to break new records in 2024.
