This small canoe demonstrates two of the most striking features of Micronesian (and some Polynesian) canoes. It uses the same principle and forces which enable aeroplanes to fly! In the case of Micronesian canoes with a single outrigger, the hull is ‘asymmetrical’. The side of the hull on the same side as the outrigger is longer than that furthest from the outrigger, just as the top surface of an aeroplane wing (front to back) is longer than the bottom. As water (or air in the case of the aeroplane) flows from front to back past the hull (or the wing) it has to go faster over the longer side and this creates a slight vacuum on the longer side. In the aeroplane this lifts the aircraft into the air. In the canoe, it reduces the displacement of the hull downwind, and allows the canoe to sail ‘closer to the wind’ when sailing towards the direction from which the wind is blowing.
When the common (‘European’) type of single-hulled sailboat is trying to sail towards the wind, the vessel ‘tacks into the wind’ by turning its bow from port (left) to starboard (right) so that alternate sides face the wind. Single outrigger Micronesian canoes with asymmetrical hulls like this one, sail towards the wind by periodically changing end to end, so that the opposite ends of the canoe alternately become the front (bow). The outrigger is therefore always on the upwind side of the hull and acts as a counterweight to the wind pressure on the sail.
Large Micronesian outrigger canoes are extremely efficient and were used for voyages over hundreds, and even thousands of kilometres. The English navigator, Commodore George Anson, reported in the 1740s that canoes in the Mariana Islands were “designed to sail as close as possible to the wind,” and could reach speeds of 20 knots (37 kilometres per hour). The asymmetrical hull was one key to this capacity, using the same forces which allow aeroplanes to fly, but centuries before the aeroplane was invented.
The second feature of many Micronesian canoes, especially those from atolls which have few large trees and thus little timber for making canoe hulls, is that they are made of small pieces of wood sewn together by coconut fibre cord. On atolls the pieces of timber will often be obtained from driftwood collected from the shore. The ‘sewn hull’ technique is clearly demonstrated in this canoe.
Emeritus Professor R. Gerard Ward, Research School of Asia and Pacific Studies, ANU
November 2012
[Learn about other Outrigger banners by searching for these Easter Eggs in the archive.]
