Jacques Cousteau himself claimed that Pigeon Island in Guadeloupe was one of the best diving spots in the world. The Jacques Cousteau Underwater Reserve is not to be missed.
Though there are plenty of sites for all experience levels, there are a couple of sites that are reserved for Advanced Open Water Divers. A particular favorite is La Grotte aux Baracudas, a gorgeous blue cave with plenty of huge barracudas.
You can find dive sites scattered around the island. You can get plenty of certifications, and mix up your excursions. French is the national language on the island, but once you’re underwater all languages become the same!
You can fly into Guadeloupe, and renting a car is a viable option for getting around. There are also taxis that can take you here and there. Another great idea is to take the ferryboats, which can send you to the islands from many other Caribbean destinations.