The King expedition two years later (1819) was expected to last eight or nine months. Their mission was to make a proper survey of the northern coast. After leaving Sydney on 8 May 1819, the "Mermaid" rounded Cape York and crossed the Gulf of Carpentaria. They then spent a substantial period exploring and surveying the coast and islands of Arnhem Land, before surveying Bathurst Island, then exploring and surveying Cambridge Gulf. They then continued their survey of the coast, past Cape Londonderry and westwards as far as the Bonaparte Archipelago. Again they crossed to Timor for provisions, then returned to Sydney.