Stewart Island, island, 674 sq mi (1,746 sq km), S New Zealand, 20 mi (32 km) S of the South Island across Foveaux Strait. Halfmoon Bay is the main settlement. A mountainous and scenic island, it is a summer resort. Frozen fish and granite are exported. Seen by Cook in 1770, it was proved to be an island by American sealers in 1804. The Maori called it Rakiura, "Island of the Glowing Sky."