What is "tuwhenua"

In Māori tradition, Tūwhenua was one of the great ocean-going, voyaging canoes (or waka) that was used in the migrations that settled New Zealand. The waka is linked to Bay of Plenty iwi. Some Māori from Ngatiira, of Opotiki, state that Tamatea came from Hawaiki in Tūwhenua, and that he found a tribe of aborigines living at Motu on his arrival