Peniche

Kondephy / Wikimedia Commons (CC BY-SA 3.0)

Crystal-clear Atlantic waters surround this granite archipelago, offering exceptional visibility over rocky reefs teeming with starfish, octopus, and schools of damselfish. Snorkelers can explore sheltered coves and dramatic underwater caves carved into the cliffs. It's a protected marine reserve, ensuring vibrant marine life just off the mainland.

Access. Accessible via a 30-minute ferry or rigid inflatable boat (RIB) ride from the harbor of Peniche. Tours operate daily during the summer months.

Notes. Water can be chilly and Atlantic swells can affect visibility and safety; check sea conditions before booking.

Portugal

Formigas — Wikipedia

An isolated reef bank situated between Santa Maria and São Miguel in the Azores, offering world-class oceanic snorkeling in exceptionally clear blue water. This submerged platform attracts pelagic species, including manta rays, mobulas, barracudas, and large schools of coastal fish. It's an unforgettable open-water experience for confident snorkelers looking for big-animal encounters.

Access. Accessed exclusively via organized full-day boat expeditions operating from Santa Maria or São Miguel islands during summer.

Notes. Open ocean conditions with potential strong currents; suitable only for experienced swimmers.

Madeira

Artur Malinowski from Warszawa, Polska / Wikimedia Commons (CC BY 2.0)

Madeira’s first marine reserve features exceptionally clear water and remarkably tame marine life due to decades of strict protection. Snorkelers swimming along the rocky drop-off frequently find themselves surrounded by large dusky groupers, barracudas, and seabream. Shore entry is available right from the pebble beach, making vibrant marine encounters accessible without a boat.

Access. Shore entry from the beach of Reis Magos or Garajau, reached via cable car or winding road down from Caniço.

Notes. Fishing is strictly banned, which explains the high density and tameness of the large fish.

Setúbal

David Francisco / Wikimedia Commons (CC BY 3.0)

Nestled inside the protected Arrábida Natural Park, this sheltered bay features calm, turquoise waters and a rich sea bottom of rocks and seagrass meadows. Snorkelers frequently encounter colorful wrasse, seabream, and occasionally cuttlefish along the shallow rocky drop-offs. The dramatic backdrop of green cliffs plunging into the sea makes it one of Portugal's most scenic coastal swims.

Access. Easy shore entry from the beach. Reached by car or local bus from Setúbal, though parking is heavily restricted in summer.

Notes. Spearfishing is strictly prohibited as it is a marine reserve zone.

Azores

Vitor Oliveira from Torres Vedras, PORTUGAL / Wikimedia Commons (CC BY-SA 2.0)

A sheltered, sandy crescent bay protected by steep volcanic hills on Faial Island, offering calm and clear waters ideal for relaxed snorkeling. The shallow rocky edges on either side of the bay harbor colorful anemones, starfish, and juvenile fish. Its historic whaling heritage and tranquil ambiance make it one of the most pleasant swimming spots in the central Azores.

Access. Direct, easy shore entry from the sandy beach right in Horta on Faial Island.

Notes. Generally calm, but watch out for occasional boat traffic near the harbor entrance.

Azores

Jules Verne Times Two / Wikimedia Commons (CC BY-SA 4.0)

A stunning flooded volcanic crater just off the coast of São Miguel forms a nearly circular natural swimming pool with calm, crystal-clear water. The protected interior lagoon is safe for snorkeling and teems with colorful Mediterranean reef fish, blennies, and wrasse. Swimming through the narrow channel connecting the crater to the open ocean adds a sense of adventure.

Access. Short 10-minute authorized boat shuttle from the marina of Vila Franca do Campo during the summer season.

Notes. Visitor numbers to the islet are strictly capped daily to preserve the nature reserve; advance booking is recommended.