Ilheu de Vila Franca
Depth is the range from the top of the site to its usual maximum; "recommended cert" is the mainstream-agency level operators usually ask for, not a legal rule. Currents and visibility change daily — treat everything here as planning ranges.
This islet is the drowned rim of a small volcano, its circular lagoon connected to the sea through a narrow channel — a geometry so neat it looks engineered. Snorkelers work the calm crater while divers circle the outer walls, where black volcanic rock carries anemones and schools of ornate wrasse, salema and white seabream. Rays settle on sand patches and octopus den in the boulder gaps. It is an easy, scenic counterpoint to the Azores' offshore adrenaline, and a protected area since the 1980s.
The moment you come for: Volcanic crater lagoon, easy reef walls, reliable summer conditions
Topography: Volcanic walls, boulders and a circular flooded crater lagoon
Entry: Minutes off Vila Franca do Campo, Sao Miguel; summer visitor numbers to the islet itself are capped.
Know before you splash
Hazards: Summer swimmer and boat traffic near the channel; mild surge on the outer walls.
Conservation: The islet is a nature reserve with capped daily visitors in summer; boats use designated moorings.
For photographers
Wide angle: ★★★★☆ · Macro: ★★★☆☆ — editors' 1–5 rating of what this site gives each style of shooting