Pata Roxas is a combined natural and artificial reef located 900 metres off the coast of Cascais, Portugal. This site offers an varied underwater landscape for intermediate divers, with depths ranging from 17 to 30 metres and an average depth of 24 metres. Access is strictly by boat. Divers should be prepared for moderate currents and visibility that fluctuates between 2 and 10 metres. Water temperatures remain between 15 and 17C throughout the year, requiring appropriate thermal protection. Navigation requires caution to avoid contact with sharp coral and rocks on the reef structure. Typical dive times are approximately 50 minutes.

Tubos is a boat-accessible dive site located off the coast of Cascais, Portugal. The reef structure extends to a maximum depth of 21 metres. Divers should be prepared for variable visibility ranging from 5 to 20 metres and mild currents. Due to the depth and potential for entrapment in cave or swim-through areas, this site is suited for advanced divers with solid buoyancy control. Water temperatures remain between 15 and 18 degrees Celsius, necessitating a thick wetsuit or drysuit. Marine life observed at the site includes common crabs and snails, alongside less frequent sightings of gray seals, cuttlefish, octopus, catsharks, wrasses, and various nudibranchs like the tricolor doris.

Principes is a shallow reef located 500 metres off the coast of Cascais, Portugal. The site features depths ranging from 5 to 8 metres, with an average depth of 6 metres, making it suitable for beginner divers. Visibility typically fluctuates between 5 and 15 metres, and currents are generally mild. Divers may encounter species such as the Tompot Blenny, European Common Cuttlefish, Common Octopus, Slipper Lobster, Tricolor Doris, wrasses, catsharks, scorpionfish, Felimare villafranca, Grey Triggerfish, Spirograph, sea hares, and various crabs. Rare sightings of the Gray Seal have also been recorded. All entries are conducted via boat, and divers must remain vigilant regarding boat traffic when surfacing.

Pedra da Nau is a combined natural and artificial reef located in Cascais, Portugal. This site offers a manageable experience for beginners, with depths ranging from the surface to 18 metres and an average depth of 12 metres. Divers enter directly from the shore to explore the reef structures. Conditions feature mild currents, though visibility can be variable. Water temperatures remain between 15 and 18 degrees Celsius throughout the year, requiring a 5 mm wetsuit and hood for comfort. Divers should remain vigilant regarding boat traffic in the area and be cautious of sharp rock formations while navigating the reef.

Furada is a reef and cave site located 500 metres off the coast of Cascais, Portugal. Accessible only by boat, the site features depths ranging from 5 to 20 metres with mild currents. Divers can encounter marine life including the common octopus, European common cuttlefish, wrasses, catshark, slipper lobster, tricolor doris, felimare villafranca, grey triggerfish, scorpionfish, tompot blenny, sea hare, crab, bream, and sea star. The cave creates an overhead environment, requiring divers to carry a torch and maintain proximity to their guide. Visibility is variable and can be limited, so checking local conditions before departure is recommended. Water temperatures range between 15 and 18 degrees Celsius.

Gruta da Pombeira is a cave dive located in Cascais, Portugal, offering an overhead environment at depths ranging from 6 to 12 metres. With an average depth of 6 metres, it provides a shallow cave experience suitable for beginners, though divers must be mindful of the overhead environment and potential entanglement risks around reef structures. Access is exclusively by boat, and currents are generally mild. Visibility can be variable and is influenced by surface conditions, so planning dives during periods of settled weather is recommended. Water temperatures fluctuate between 15C and 19C throughout the year, necessitating appropriate thermal protection.

Praia da Poça is a shore-entry reef site in Cascais, Portugal, suitable for beginners and snorkellers. The site features a shallow reef with depths ranging from 2 to 8 metres, averaging 4 metres. Visibility typically spans 5 to 15 metres with mild currents. Water temperatures range from 15C to 19C, necessitating a wetsuit. Species recorded around this area include common octopus, European common cuttlefish, and various nudibranchs such as the tricolor doris. Facilities at the site include parking, toilets, showers, and a café. Divers should exercise caution as the reef structure contains sharp surfaces, and monitor depth closely due to the presence of deeper drop-offs in the vicinity.

Boca do Inferno is a reef site in Cascais, Portugal, named for the large rocky recess found along the coast. Divers explore depths ranging from 9 to 16 metres, where the reef structure transitions into sandy bottoms. The site features various gorges and is known for its diverse marine life, including common octopus, scorpionfish, catsharks, and various wrasses. Nudibranchs such as the tricolor doris and felimare villafranca are also present. Due to strong currents, surge, and surf, this site is suited for intermediate divers. Shore entry is required, and conditions vary with visibility ranging from 1 to 25 metres. Water temperatures remain cold, typically between 15C and 18C throughout the year.