Detail from Charles Wilkes' 1840 map of Antarctica. Wilkes provided the first evidence that Antarctica was a continent. This detail shows the area where James Cook's 1773 map finished. (See a full zoomable version of this map on the David Rumsey Collection website.)
Tuati was probably the first New Zealander to view the coast of Antarctica, in 1840. He was part of the United States Exploring Expedition, which explored the southern oceans between 1838 and 1842. The expedition, led by Lieutenant Charles Wilkes, notably provided the first evidence that Antarctica was a continent.
Tuati, also referred to by his European name, John Sac, was the son of whaler and sealer Captain William Stewart (after whom Stewart Island is named), and his Ngapuhi wife. He arrived in the United States on board a whaling ship in the mid-1830s, joining Wilkes' expedition in 1838.
Maori tradition suggests that a Polynesian chief by the name of Hui Te Rangiora may have been the first person to see Antarctica. He is said to have encountered the icebergs of Antarctica in 650 AD during a voyage south of New Zealand.
Tuati worked as a seaman but also accompanied Wilkes as his interpreter when the expedition stopped in French Polynesia. Wilkes wrote of ‘Tuatti' in his detailed narrative of the expedition, Narrative of the United States Exploring Expedition, commenting that he ‘was an excellent sailor, a very good fellow'.
Tuati left the expedition in the Hawaiian Islands in October 1840, on the expiration of his term of enlistment. He subsequently migrated to Australia with his father and younger brother.
In 1993 the New Zealand Geographic Board named a peak in Antarctica after Tuati. Tuati Peak stands at 2595 m, rising above the north wall of Mitchell Glacier at the glacier head, in the Royal Society Range, Victoria Land.