Due to the presence of several marine reserves, diving in Saint-Barthélemy is a must. Diving in St-Barthelemy is much safer than in many others spots for the main reason that it's impossible to overpass a depth of 30 meters in the surroundings. Underwater landscapes are diversified and very scenic 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 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.