 During pre-European-contact times there was frequent canoe voyaging between the islands as Polynesian navigation skills are recognised to have allowed deliberate journeys on double-hull sailing canoes or outrigger canoes.Eight of the nine islands of Tuvalu were inhabited; thus the name, Tuvalu, means "eight standing together" in Tuvaluan (compare to "*walo" meaning "eight" in Proto-Austronesian).Possible evidence of fire in the Caves of Nanumanga may indicate human occupation thousands of years before that.