Gombessa VI

To the north of Cap Corse, more than 100 meters under the sea, exist strange formations that have never been studied before: perfectly round rings 30 meters in diameter. How these coralligenous atolls are formed and where they come from remains unknown. The Gombessa team, led by Laurent Ballesta, intends to solve this mystery.

In 2011, during a mapping campaign conducted off the coast of Cap Corse by IFREMER (French Research Institute for Exploitation of the Sea), a thousand strange and perfectly circular formations, regularly outlined on the seabed between 115 and 140 m, appear on the monitoring screens. Never explored, these immense coralligenous atolls (each one 30 m in diameter) are a great mystery. What is their origin? What are the reasons for their presence in the Mediterranean?

To provide answers to these questions – and many more – Laurent Ballesta and three divers from the Gombessa team boarded the now famous Bathyale Station, set up on the barge of the INPP (National Institute of Professional Diving) on July 1st, 2021. During Gombessa V in 2019, for the first time it enabled them to associate saturation diving with recreational deep diving using closed circuit rebreathers. Thanks to this technique, this year the aquanauts were able to explore the great depths of the Cap Corse and Agriate Marine Natural Park during very long dives over a 20-day period, punctuated by numerous research protocols.

Over and above the scientific aspect, this expedition came with a major physiological challenge, as the four comrades stayed in a five square-metre pressurised chamber – an extreme environment for humans. Laurent Ballesta brought back unprecedented images from his journey to discover the "coral rings" of the Mediterranean. The mission will eventually confirm or refute the hypothesis that the formation of these curious aggregates is linked to gas emissions or freshwater springs.

Blancpain is delighted to have contributed to the achievement of this project, which is part of an ongoing process. Laurent Ballesta had already travelled to Corsica in May 2021 to study the angel shark, a species that seemed to have disappeared from the French Mediterranean. It was back in 2020, during an extraordinary mission with the aim of studying the impact of the cessation of human activities on vertebrate and marine invertebrate populations following the Covid-19 pandemic, that Laurent Ballesta had found signs of this animal which is halfway between shark and ray.