

Best for advanced divers, 6-233m, shore entry, mild current.
Exsurgence de Port-Miou is a significant submarine freshwater spring and flooded karst system located near Cassis. This advanced technical site features depths ranging from 6 to 233 metres, with an average depth of 40 metres. Divers encounter a challenging overhead environment with cold water temperatures between 14 and 16 degrees Celsius and visibility typically limited to 5 to 10 metres. Marine life observed in shallower sections includes snails, crabs, hermit crabs, bream, white seabream, and hard coral. Due to risks including entanglement, surge, and strong currents, this site is strictly for divers with appropriate cave, cavern, and technical certifications. Shore entry is required, with facilities including parking, showers, and a café available.
43.20517, 5.51291
Cave, cavern, deep, trimix, and rebreather certifications are all required depending on how far into the system you intend to go, so carry your relevant certification cards and confirm your planned penetration depth against your qualifications and gas supply before entering. Parking, showers, changing rooms, and a café are available at the site, making logistics straightforward for an early start.
The site is dedicated to scientific research and exploration and is not open to the public.
Recorded nearby, within 20km
Depth
6-233m
Visibility
5-10m
Skill Level
Advanced
Entry
Shore
Water Temp
14-16°C
Current
Mild
Typical Dive
60 min
Divers may encounter snails, crabs, hermit crabs, bream, white seabream, and hard coral in the shallower sections of the site.
No, this site is for advanced technical divers only. It requires specific cave, cavern, and deep diving certifications due to the extreme depths and overhead environment.
The site reaches depths of 233 metres, with an average depth of 40 metres.
The site is accessed via a shore entry.
Snorkelling is not recommended due to the site's nature as a deep, technical cave system with significant overhead hazards.
Diving at Exsurgence de Port-Miou in Cassis requires the following certifications: Cave, Cavern, Deep, Trimix, Rebreather. Always dive within your training limits.
A 7mm wetsuit or semi-dry is recommended for diving at Exsurgence de Port-Miou in Cassis. Water temperatures range from 14°C to 16°C.
Exsurgence de Port-Miou in Cassis typically has mild currents that most divers can handle comfortably.
Visibility at Exsurgence de Port-Miou in Cassis typically ranges from 5 metres to 10 metres. Conditions vary with weather, tides, and seasons.