The distance nobody mentions in the photo caption
Benagil is the most photographed sea cave in Portugal and it sits well west of Vilamoura. From Marina de Vilamoura — the charter base of the central Algarve — reaching it is a half-day commitment: the cave only appears on charters of 5 hours or more, and is sold as a dedicated 4 to 5 hour private itinerary. Charters here are bought in blocks from about 2 hours up to 10 hours, so this is a decision about which block, not a small add-on.
For comparison, the same cave is about 1.5 hours round trip by speedboat from Portimão and about 2 to 2.5 hours from Albufeira. We would rather tell you that up front than sell you the long way round.
What the rules actually allow now
Benagil is regulated. Harbourmaster edicts in force since 13 August 2024, and amended in July 2025, ban swimming or floating into the cave, ban disembarking on the cave beach entirely, restrict entry to licensed vessels and cap both the number of boats inside and the time each spends there. In practice a licensed boat gets roughly 5 to 10 minutes inside. Breaches carry fines from €200 up to €216,000.
That changes what a good trip looks like. The cave is now a passage rather than a picnic, and the rest of the coastline — arches, grottoes, swim stops in coves without names — is where the day is actually won.
Boats, and what gets inside
The boats that can work the cave mouths are small, around ten people or fewer. A private yacht from Vilamoura gives you the deck, the shade and the swimming; it does not give you a tight cave entrance. Where a combination is possible, we say exactly how it works before you book rather than leaving you to discover it at the cliff.
What it costs, honestly
Vilamoura private charters run from about €900 for a 47-foot boat up to about €3,500 for a 72-footer, by size and block — treat the lower number as an entry point rather than a rate for this itinerary. Shared cave tours from the marinas nearer the cave sit at roughly €19 to €45 per person, which is the fair comparison if budget rather than privacy is the driver.
Season, swell and the honest advice
Peak is May to October. The constraint is Atlantic swell, not wind — calm at the beach can mean dangerous water at the cave mouth. Early departures usually beat both the swell build and the boat queue.
Boats are run by Portuguese maritime-tourism businesses registered with Turismo de Portugal under RNAAT; we arrange and confirm the day, they run it. Free cancellation up to 24 hours ahead is the market norm, with weather cancellations normally resolving as a reschedule or refund on the boat’s terms, in writing first. More Algarve days and our boat charter approach.