D. Gordon's letter re early Maori navigation is surely misguided? Even if in recent times details are 'translated” into and described in modern terms.
Navigation of the oceans was established early in history, using whatever methods the age and location offered. But in N. hemisphere (but not only) sophisticated instrumentation was already in use, where a wide variety of materials eg metals, was explored and access to mathematics used.
Maori worked basically in wood, which would surely not have served for such precise instrumental construction. (I was interested to read that they were, technically, 'stone age” people.)
Evidently those well constructed, large double and multi hulled canoes with many fit and dedicated paddlers could achieve high speeds and distances. It would have taken a taken a high level of skill, practice, and intelligent observation to access and use all the many environmental clues in order to navigate accordingly. My ignorant summing up, but to give credit where it is due, to those sailors!

D. Holm, Tauranga.