Windows to the Deep: APNEA’s Submerged-View Cruise from Sesimbra to Ribeiro do Cavalo

Situated along Portugal’s sun-drenched Setúbal coastline, Sesimbra offers a natural gateway to one of the country’s most vivid marine environments. Aquarama invites adventurers and families alike aboard their vessel APNEA for the Passeio com Visão Submarina, a two-hour journey combining coastal beauty with underwater observation — without ever getting wet. Departing from Sesimbra’s historic harbor, this unique excursion pauses at three underwater viewing points where large plexiglass windows reveal the vibrant life beneath the waves.

The boat’s slow glide along the rugged coast reveals secret beaches and cliffs topped by the lush greenery of Serra da Arrábida, a protected natural park. Below the waterline, dense beds of various seaweed species carpet the sandy seafloor, providing habitat for a variety of fish, mollusks, and crustaceans. These underwater glimpses offer an intimate look at the ecosystem’s layers, from delicate wrasse darting among rocks to graceful rays settling in shaded coves.

The trip culminates at Praia da Ribeira do Cavalo, a secluded beach widely regarded as Portugal’s most “Thai-like” shore for its clear turquoise waters and pristine white sand, accessible primarily by boat or steep trail. Here, passengers can relax in the serene atmosphere, a marked contrast to the busier coastal towns nearby.

Beyond the natural attractions, Aquarama’s commitment to safety and comfort stands out. The vessel features a spacious 60m² social area, onboard soundscape, private restrooms, and changing facilities. Knowledgeable local guides provide narration, illuminating both natural history and conservation efforts in the Arrábida marine reserve.

This marine-vision experience fills a niche in the region’s outdoor recreation—bridging the gap between sailing, wildlife education, and family-friendly adventure. For visitors staying in Lisbon or nearby Setúbal, it offers a fresh perspective on Portugal’s coastal biodiversity without the need for snorkeling or diving gear. It’s an accessible, immersive way to connect with the sea that defines this part of the Atlantic coast.