Corps de Garde

Ten to forty metres, and air that does not last the same

Town : Sainte-Luce

Corps de Garde is dived opposite the beach of the same name, in Sainte-Luce bay, three kilometres from the town. The register of Martinique sites files it at number 69, as Corps de Garde and caye Philippeaux, next to Poids Perdu.

It is also from here that our outings to Grande Caye and Trois Vallées set off.

The site really offers two dives. A classic exploration between ten and twenty metres, among corals, sponges and multicoloured fish. Or a deep one, on a wall starting around thirty-six metres and finishing near forty, with an ascent at the end onto a plateau covered in gorgonians, some of them a metre tall. Visibility is good, with current at times.

The deep version is reserved for very experienced divers, guided, planned and scouted beforehand. It is not a dive you improvise on the morning.

Why your air goes faster down there

This is physics, and it does not negotiate. At ten metres, pressure is twice that at the surface. At thirty metres, four times. At forty, five times.

Your regulator delivers air at the pressure surrounding you. At forty metres, every breath therefore empties your tank five times faster than at the surface, for exactly the same volume breathed. A tank that lasts an hour at ten metres does not last half that at forty.

The three things that change your consumption

• Depth, the only one you cannot argue with.
• Effort. Swimming against the current, fighting badly adjusted weighting, or simply finning too fast, can double your consumption.
• Calm. A tense diver breathes fast and badly. That is why a beginner uses far more than a regular on the same dive, and why the gap closes by itself with experience.

What that changes on this site

On the deep dive, your endurance is counted in minutes, not hours. That is why this version is planned, scouted in advance, and not open to everyone. The twenty-metre dive, by contrast, leaves all the time in the world to look.

What level you need here