There is a persistent theory that Vikings found their way to the South Seas, and settled (amongst other places) in New Zealand.
Speakeing personally, I'd have no at all difficulty believing this theory: their longboats were more than sufficiently seaworthy, and they had an idea-or-two about how to do long trips by boat.
And this would explain several persistent Maori tales about blond, white, faerie people who inhabited New Zealand before the Maori settled here.
It has also been postulated that the Phoenecians got here, at some point, prior to the big Taupo volcanic explosion. Again, I have no difficulty believing this.
Worst case scenario: if you were on a log, cast adrift somewhere in the South Pacific, the prevailing currents would in all likelihood sweep you toward NZ and wash you ashore. Or, at least, that is my reading of the maps...
My neighbor is from NZ. He said the Maori ate the White people.