Calanque de Monasterio is a remote reef site located on the uninhabited Île de Riou. Accessible only by boat, this location features white sandy bottoms and is situated within the National Park. The site is suitable for intermediate snorkellers, offering a 5/5 rating for the activity. Water temperatures fluctuate throughout the year, ranging from 14C in the winter months to 24C in August. Due to its distance from the shore, approximately 14 kilometres, visitors should be prepared for moderate currents. The site provides a quiet environment for observing the underwater topography of the Riou Archipelago.

Les Deux Jumelles is a deep reef and wall site located off the Île de Riou. The topography consists of a steep wall dropping to depths between 57 and 65 metres, with an average depth of 61 metres. This site is strictly for advanced divers with deep diving certifications, as the depth presents the primary hazard. Conditions include mild currents and visibility ranging from 5 to 10 metres. Due to the significant depth and water temperatures between 13 and 18 degrees Celsius, a drysuit or thick wetsuit with hood and gloves is recommended. Boat access is required, and guided tours are available locally to assist with navigation and safety.

Le Couloir aux gorgones is a boat-access reef located off the Île de Riou near Marseille. The site features depths ranging from 25 to 36 metres, requiring appropriate depth certification and buoyancy control. Divers typically encounter moderate currents, making it necessary to plan dive profiles carefully and utilise the reef for shelter. Visibility at the site varies between 10 and 30 metres depending on local conditions. Water temperatures fluctuate between 13 and 19 degrees Celsius throughout the year, necessitating a thick wetsuit or drysuit for thermal protection. Given the depth and current, this site is best suited for experienced divers.

Grotte du Corail is a cave and reef site located off the Île de Riou. This site offers a combination of open-water reef diving and an overhead cave environment, with depths ranging from 15 to 30 metres. Divers encounter Mediterranean moray, scorpionfish, wrasses, and various nudibranchs including Cratena slug and tricolor doris. Visibility typically spans 10 to 25 metres. Due to the overhead environment and sharp rock surfaces, solid buoyancy control is essential. The site is accessible only by boat and is suitable for intermediate divers. Water temperatures fluctuate between 14 and 20 degrees Celsius throughout the year, and night diving is permitted.

Les Pierres Tombées, located off the Île de Riou, features a combination of reef and drop-off topography. The site ranges from 15 to 29 metres in depth, with an average of 20 metres. Divers can explore shallower reef sections before reaching the deeper edge. Visibility typically spans 10 to 30 metres. The site is suitable for beginners, though a moderate current requires careful buoyancy management. Marine life includes common scorpionfish and various wrasses, alongside less frequent sightings of Mediterranean moray, great barracuda, common octopus, and several species of nudibranchs and flatworms. Boat access is required, and a 5 mm wetsuit is recommended due to water temperatures between 14 and 18 degrees Celsius.

Tombant de David is a shore-entry wall and drop-off site located at Île de Riou. The topography descends from 10 to 40 metres, with an average depth of 20 metres. Divers encounter moderate currents along the vertical seascape, making this site suitable for intermediate divers. Water temperatures range from 14 to 17 degrees Celsius, necessitating at least a five-millimetre wetsuit. Visibility can be variable, requiring careful orientation in deeper sections. Marine life recorded here includes Mediterranean moray, great barracuda, wrasses, scorpionfish, and various nudibranchs such as the Cratena slug, Mediterranean violet aeolid, and Felimare orsinii. Other inhabitants include cow snails, flatworms, gorgon's head, Turkish wrasse, tricolor doris, flamingo tongue, and squat lobster.

L'Impérial du milieu, located off the Île de Riou, is a diverse site featuring a combination of reef, wall, and canyon topography. Divers can explore depths ranging from 5 to 46 metres, with an average depth of 25 metres. The site is suitable for intermediate divers and requires boat access. Conditions include moderate currents and visibility between 10 and 30 metres. Marine life is abundant, with common sightings of Mediterranean moray, wrasses, scorpionfish, flatworms, and cow snails. Less frequently, divers may encounter great barracuda, Turkish wrasse, Gorgon's head, and various nudibranch species including Cratena slug, Mediterranean violet aeolid, Felimare orsinii, tricolor doris, giant doris, and flamingo tongue.

Bosse du Chameau is a reef site located at Île de Riou, France. The site features a profile that drops from the surface to a maximum depth of 42 metres. Due to the depth and variable conditions, it is suited for intermediate divers. Access to the site is by boat only. Visibility and currents are variable, so it is recommended to consult a local dive operator to determine the best window for your visit. Water temperatures range from 13 to 19 degrees Celsius throughout the year, necessitating appropriate thermal protection such as a thick wetsuit or drysuit, particularly when exploring the deeper sections of the reef.