Banco Dom João de Castro

Banco Dom João de Castro is a shallow submarine volcano between Terceira and São Miguel that has erupted as recently as 1720, leaving a summit just 14 m below the surface surrounded by a landscape of fresh lava flows, sulphurous vents, and pioneer reef colonisation. Hydrothermal gases bubble from cracks in the basalt, and the water carries a faint mineral warmth near the summit. Schooling barracuda and amberjacks patrol the shallower ridges while oceanic whitetip sharks and blue sharks sweep through in the blue beyond the crater rim. The geological drama and the contrast between barren new lava and thriving colonised rock makes this one of the Azores' most unusual and memorable dives.