Aljezur Seamount

Rising from 80 metres to within 25 metres of the surface on the exposed Costa Vicentina — Portugal's wild west coast — the Aljezur seamount intercepts the full force of Atlantic upwelling, concentrating nutrients that support one of the richest pelagic ecosystems on the Iberian margin. Mola mola (ocean sunfish) are reliably encountered here from July through October as they ascend to shallow water to be cleaned by wrasse, and the summit's rocky pinnacles are draped in large gorgonian sea fans indicating decades of low fishing impact. The site requires a live-aboard or strong-boat operation and is reserved for experienced divers comfortable with open-ocean conditions.