On the southern edge of Portugal’s Algarve, the speedboat tour Passeio de lancha pelas grutas do mar de Benagil launches from Portimão and darts along a coastline carved of brittle limestone. This 1–2 hour ride—fast, splashy, and often sunlit—threads together sheer cliffs, secret beaches, and the luminous chamber of the Benagil sea cave, one of the region’s signature geological features. Meet at the ruins of the Convento de São Francisco in Portimão for a safety briefing, life-jacket fitting, and a chance to watch the crew check weather and swell. Once aboard the new fiberglass speedboat, the coastline unfolds: ochre and cream cliffs scored by wave erosion, narrow grotto mouths, and stacked rock ledges where seabirds loaf. The itinerary typically passes Portimão pier, Castelo Ferragudo, the paradisiacal caves near Benagil, Carvoeiro’s coves, Algar Seco’s sculpted platforms, Farol Alfanzina’s stoic light, and the working harbor at Porto Docapesca. The crown jewel is the Benagil cave—a large, rounded chamber with a natural skylight formed where the Atlantic hollowed out a limestone dome. Photographers chase the pinprick of sunlight on the sand; geology fans note the layering of Miocene limestone and younger calcarenite that gives the cliffs their striping. Keep an eye on marine life: common dolphins cruise these waters, though sightings aren’t guaranteed. This operator’s speedboat format makes places accessible that rigid hulls and large ferries can’t reach, trading a slower, quiet approach for speed and intimate cave corridors. That also means the ride is not wheelchair accessible and is not recommended for people with back or cardiac conditions or for pregnant travelers. Bring seasickness precautions if you’re sensitive; the crew provides a safety briefing but the experience can be brisk. Why book it? If you’re short on time but eager to sample Algarve’s coastal geology and hidden beaches, the tour concentrates highlights into a compact, adrenaline-tinged trip. It’s especially useful as a launching point for independent exploration—scan the coast for swim-friendly coves you might return to on foot or kayak. Practical note: reservations are allocated automatically, so if you book separately but travel with a group, tell the operator which reservations belong together. Dolphin encounters are possible but not promised. For a snapshot of the Algarve’s layered cliffs, cathedral-like caverns, and wind-shaped rock, this speedboat run is an efficient, memorable way to feel the Atlantic along Portugal’s southern shore. A brief safety talk covers life jackets, boarding, and how to approach cave mouths; crew members are trained to advise if conditions make a passage unsafe. The trip suits older children but not infants, and ask about private charters if you want longer beach landings—otherwise this run gives a sharp, scenic orientation before you tackle the Algarve’s clifftop trails.