It is about forty kilometres (25 miles) long and 25 km (16 mi) wide, covering a total area of 514.49 square kilometres (199 square miles) (including small offshore islands such as Rani but excluding the neighbouring Aruri Archipelago.

South of Supiori lie the small coral islands Aruri (Insumbabi) and Rani.

[1] One of the first sightings was also made by the Spanish navigator Álvaro de Saavedra on 24 June 1528, when trying to return from Tidore to New Spain.

The Schoutens were charted as Islas de Oro (Golden Islands in Spanish).

It was charted as Los Martires by the Spaniards, possibly because it was where Spanish navigator Hernando de Grijalva was murdered by his mutinied crew.