The DEEP BLUE EXPLORATION team had the first 15 days of January 2024 to take the data necessary to carry out a 3-dimensional modeling of the cave of karst origin which is located near the boat pass to the south of the lagoon of Mayotte. To do this, a team of 4 tek divers with their closed circuit rebreathers dove for 12 days between 50 and 80 meters deep in the narrow guts of the depths of the Mayotte lagoon.

By setting up this expedition, Gaby BARATHIEU presents his team but also himself with a challenge: to carry out a complete modeling of an underwater cave of karst origin, with architecture and a winding route. Composed of several large rooms and narrow spaces, collapsed blocks, stalagmites and stalagtites (most often fallen to the ground by ancient earthquakes) but also a large area of very volatile sediment deposition, this geological singularity (long of more than 130 meters) specific to Mayotte and the Indian Ocean questions many scientists.

This fine 3-dimensional modeling will allow scientists to have a global vision and a better understanding of its formation during the last geological era. Indeed, there are still many questions that remain unanswered, in particular on its disturbing orientation which seems to point towards the interior of the lagoon while it should normally be oriented towards the external slope, towards the exterior of the lagoon.

Transmitting the atmosphere, the “mood” and the very particular atmosphere of these karst environments steeped in history is one of the main drivers of our explorations and our expeditions. There are different ways to achieve this. Whether through photography or video, none of these media allow total immersion in the darkness of this cave. 

However, we are only a few privileged divers who have the technical capabilities to explore this hostile environment. To date, fewer than 10 people have had the privilege of seeing the “stalagmite field.” 

The fruit of the Gumbo La Baharini 3D mission will be able to transmit these emotions and share this fabulous immersion in time and within the floor of the lagoon with everyone.

This ambitious and (a little) crazy mission to model a karst cave in the mesophotic zone (between 50 and 80 meters deep) is above all a human adventure. The team of 10 people including 4 TEK divers equipped with closed circuit rebreathers dived for more than 10 days inside this hole open on the floor of the lagoon and rushing into the bowels of the latter like the waves of rivers which were at the origin of its creation.

Its position being close to the boat pass, the entrance to the gallery is subject to very strong incoming or outgoing currents which can easily reach speeds of more than one knot. The release of tek divers with all their equipment (rebreather, Bail out, DPV) must be adjusted every day and carefully orchestrated to have the best possible efficiency. It is not permitted to wait on the surface or take your time to descend to the depth of 50 meters. Depending on the conditions, it is not uncommon for the launching point to be more than 200 meters (upstream or downstream depending on the current) from the entrance. Proof of this is that the first two days of the mission, the divers were unable to find the entrance to the cave under the effect of the strong current and the poor visibility of the water which persisted throughout the assignment.

We never tire of the atmosphere that reigns in these dark tunnels even after more than 50 dives. Each immersion is unique and makes us discover new forms, new concretions which had until now escaped the beam of our lamps. The trimix mixture breathed also strongly influences the diver's perception. This was particularly visible when we opted for a mixture richer in helium (10/70 instead of 10/50)!

Certain portions of the main gallery are cramped and do not allow all divers to reach there without lifting the fine sediments which cover the concretions of the ground. Once the sediments are suspended, the mission objective is seriously impacted. A reduced team of only two divers (the DPV operator and the Cameraman or photographer as security operator) while the other two divers are busy setting location targets or taking sediment samples. @Gaby BARATHIEU