Cabeço Submarino is an outer-sea reef off Sueste Bay in Fernando de Noronha, known for a spiral rise that lets divers trace the formation on a flowing circuit. The reef combines rocky structure with lively fish life, including barracudas, turtles, lobsters, schooling fish, and the occasional shark. Plan it as a boat dive with an authorized local operator, since the site sits inside the marine park and responds quickly to sea state. The best windows tend to come when the outer sea settles in late autumn.