Te Waka o Rangi

Maori sky reckoning draws figures on a scale the Greek list never attempts. Te Waka o Rangi is a canoe whose prow is at one end of the visible Milky Way and whose stern is at the other, taking in the stars the Greek tradition divides between Scorpius and Orion, and treating the whole sweep as one object.

The scale is a design choice and it comes from the use. Polynesian navigation reads the sky for direction and for season, at sea, often with part of the sky obscured, and a small pattern that happens to be behind a cloud is no help. A very large figure whose parts can be identified separately and referred back to the whole keeps working when conditions are bad.

The canoe also does the year's work. As it turns through the sky it hauls the Pleiades up into view, and that rising is the event that opens the new year. The figure is not decorative. It is the mechanism by which the calendar arrives, and the canoe is doing the work rather than illustrating it.

The hook of Maui, the fishhook at the tail of Scorpius, is at the prow end and is sometimes described as trailing from the canoe. The parts of the Polynesian sky connect to one another in a way the Greek constellations, drawn as separate figures on a globe, generally do not.

Polynesian voyaging navigation uses no instruments and does not use a chart. What it uses is a star compass: a memorised set of rising and setting points around the horizon, each identified by a named star, and a sequence of stars that rise at the same bearing one after another through the night, so that as one climbs too high to be useful the next takes its place.

That requires an enormous amount held in the head. A navigator learns the rising and setting bearings of a large number of stars, the seasonal changes, the swell patterns, the flight of land-finding birds, cloud behaviour over islands, and the reference island method by which the canoe's position is tracked against an island not visible and not on the route.

The tradition was very nearly lost. Its survival ran through a small number of holders, notably Mau Piailug of Satawal in the Carolines, who navigated Hokule'a from Hawaii to Tahiti in 1976 without instruments and then taught the method to Hawaiian and other Polynesian students against the practice of his own community, on the ground that it would otherwise die with him.

The voyaging revival that followed is one of the reasons the sky figures are documented at all, and it makes the astronomy a living practice rather than an ethnographic record.