Due to the presence of several marine reserves, diving in Saint-Barthélemy is a must. Diving St-Barth is much safer than in many others spots as the greatest depth in the surroundings never overpass 30 meters. Underwater landscapes are diversified and very nice with a rich biodiversity made of sponges, corals, fishes, turtles, squales. Several species of Gorgonias can be observed. They are very useful to paleoclimatologists that analyse the gorgonin and calcite they are made of. Thereby, scientists get a better understanding of the past earth climates at a time when no direct mesures were available. This provides a better understanding of the today climate change.