Cap Caveau is a sheltered Frioul cove with a shallow start, a rocky plateau, and a longer outer drop-off. The main line stays on hard bottom and fishy ledges, while a submerged hole in the rock adds a more serious feature for trained overhead divers. It is usually reached by boat and works best when Marseille's windier sites are less comfortable. Expect a calm Mediterranean dive with typical fish life, seahorses, and the chance of blue-water passers.