The voyage was called the hiri, and it was not an occasional adventure: it was a people's food system, repeated every season for centuries and synchronised to the calendar of the wind.
01 An economy born of a shortage of water
Port Moresby receives 899 millimetres of rain a year, the lowest figure in all of New Guinea, and its dry season is long and severe. In those conditions there is no way to sustain the sago palms that feed much of the country.
Their neighbours in the Gulf of Papua, a few hundred kilometres to the north-west, had the opposite problem: sago to spare and no pottery tradition. The Motu, by contrast, worked clay: the women shaped and fired the uro, the cooking pots used all along the coast.
The exchange organised itself. Pots west, sago east, and one annual crossing to move it all. The shortage of water did not impoverish the Motu: it turned them into traders.
02 Vessels of several hulls
Carrying that volume took more than a canoe. The lakatoi — the word means literally 'three hollowed logs' — was built by joining two or more hulls with booms and laying a continuous platform on top.
Above it rose two crab-claw sails of matting, with that unmistakable silhouette that appears in nineteenth-century photographs and on the stamps of the period. They were slow, stable craft, built to carry weight rather than to sail close to the wind.
Preparations began at the end of September. The men assembled the lakatoi while the women shaped and fired the pots, and when the south-east trade — the laurabada — began to blow steadily, the little fleet headed west.
03 Out on one wind, back on the other
The outward leg was the easy part: barely a week of sailing downwind to a village in the Gulf where the crew was already known from previous voyages. The trade itself was settled quickly.
But they could not go back. They had to wait for the season to turn and the lahara to arrive, the north-west monsoon, the only wind that could carry them home. And they had to rebuild the vessel: add hulls and widen the platform to carry the sago, far bulkier than the pots.
Two or three months later the return began, and that was the dangerous part. The lahara season brings heavy seas and severe storms, and the lakatoi came back overloaded and with more hulls than they had left with, which did nothing for their handling.
04 The language the business left behind
To deal with trading partners who spoke other languages, the Motu used a simplified version of their own. That reduced form spread along the coast as the lingua franca of trade.
Later the colonial police force adopted it, and for decades it was known as Police Motu. In the 1970s a committee decided to rename it Hiri Motu, precisely to acknowledge that its history was older than the police force and came from those voyages.
Today Hiri Motu is one of the three languages Papua New Guinea's constitution names alongside English and Tok Pisin, although its use has been retreating in favour of both for years: an estimated 95,000 people speak it as a second language.
05 What it reveals
The voyages continued, interrupted only in the 1940s, until the late 1950s, when an overloaded, storm-damaged lakatoi foundered off the village of Boera on its way home, with heavy loss of life. The colonial authorities forbade any more of them.
Since independence, a festival has recreated the arrival of a lakatoi, timed to the national celebrations. It is not the same thing, but it keeps visible an idea that is easily forgotten: that here the wind had a calendar, and eating depended on respecting it.
Next time you read that Port Moresby is the driest city in New Guinea, add the other half of the sentence. That dryness forced a people to become sailors, potters and traders, and left a language in the country's constitution.
