Piailug grew up on a tiny (less than 3km long) island where survival required sailing far out to sea for deep water fishing. The inhabitants of the island were experts in navigation using stars, winds, birds and various other signs available before the advent of modern navigation.
Piailug began studying to be a master navigator with his grandfather at age 5 and was the last local to learn navigation in the traditional way. From the article:
“He could read how far he was from shore, and its direction, by the feel of the swell against the hull. He could detect shallower water by colour, and see the light of invisible lagoons reflected in the undersides of clouds. Sweeter-tasting fish meant rivers in the offing; groups of birds, homing in the evening, showed him where land lay.”
He became famous by successfully sailing a little double hulled canoe from Hawaii to Tahiti using no modern equipment at all. In an expedition reminiscent of the great Kon Tiki journey he did so to prove that it was possible for ancient navigators to do so.
In his later life Piailug taught others the ways of navigation, this time allowing them to make notes and record the ancient knowledge. If he hadn’t done so, this amazing knowledge would have been lost to us forever.