United Tribes flagThe idea of a flag to represent New Zealand was first broached in 1830, when the Hokianga-built trading ship Sir George Murray was seized in Sydney by Customs officials for sailing without a flag or register. Australia, New Zealand's major trading market, was subject to British navigation laws which ruled that every ship must carry an official certificate detailing construction, ownership and nationality of the ship. At that time, New Zealand was not yet a British colony and New Zealand-built ships could not sail under a British flag or register.