Colster, Willem Joosten Van, a Dutch explorer, charted the west coast of the Gulf of Carpentaria, in Northern Australia. In 1623, he sailed in the Arnhem from Batavia (now Jakarta, Indonesia) to Nova Hollandia (New Holland), now Australia. Together with the Dutch explorer Jan Carstensz in the Pera, he charted the west coast of Cape York Peninsula. The ships separated, and Colster continued southward. He sailed across the Gulf of Carpentaria to what is now Arnhem Land. He anchored at the Wessel Islands and then returned to the Dutch East Indies. Historians know little more about Colster.