Not an ocean beach at all — Cavacos is a pocket of sand on the mainland edge of the Ria Formosa near Olhão, facing the lagoon’s channels and sandbanks rather than open Atlantic. The water is calm, shallow and tide-ruled: at high water you get a swimmable lagoon; at low water the ria drains into ribbons and flats, and the birds move in.
That rhythm is the photograph — moored boats sitting on wet sand, long reflections, the flat bright light of the eastern Algarve. It suits swimmers with small children, birdwatchers, and anyone more interested in the ria’s geometry than in surf.
When to go: around high tide for swimming, low tide for the drained-lagoon look. Summer weekends draw local families; otherwise it’s quiet.