In an archipelago of low atolls, land is barely visible. An islet three metres high drops below the horizon within a few kilometres, so navigating by what you can see is impossible almost all the time. What does travel far, and steadily, is swell.
01 A map that does not map land
The materials are local: coconut-frond midribs tied together with fibre into an open framework. Shells, or sometimes the knots themselves, mark the positions of islands.
But the main information is not in the shells: it is in the sticks. Each represents a swell direction, and the curves show how that wave bends as it passes an island and where it intersects another.
The system distinguished four main swells by strength and origin: rilib, the strongest, associated with the north-east trade wind; kaelib, weaker and present all year; bungdockerik, from the south-west and noticeable in the southern islands; and bundockeing, the weakest, mainly in the north.
02 Three kinds of chart
The mattang is the most abstract: it represents no particular place but the general principles of how waves behave when they meet land. It was for teaching, not for navigating.
The meddo does represent a real place: the position of the islands along a section of chain, the directions of deep-ocean swell and the distance at which each island starts to register in the water.
The rebbelib is an expanded meddo: it covers a complete chain, or even both of the chains that make up the archipelago. It is the kind of chart used for long crossings between atolls.
03 Memorised, not consulted
Here is the detail that usually surprises most: the charts were not carried in the canoe. They were studied on land, memorised and left at home. On board there was nothing to look at.
The knowledge was restricted. Only certain leading families held it, and it passed from father to son, which made it at once a technique and an inherited asset.
Voyages were made in squadron: several canoes sailing together under an expert navigator. That navigator was, in practice, the instrument.
04 Reading the sea with the body
The reading was not visual but tactile. The navigator crouched or lay face down in the bottom of the canoe to feel how the hull pitched and rolled with the different swells crossing beneath it.
What he was after was the interference pattern: when two waves cross, the meeting point has a characteristic motion, and that point indicates the direction in which land lies even when no land is visible.
The system remained in use for navigation until the middle of the twentieth century. It was displaced by electronic navigation and by the decline of regular canoe traffic between atolls, not by any sudden loss of knowledge.
05 What it reveals
What is interesting is not the craftsmanship but the change of premise. The West mapped the Pacific by drawing where the land was; here it was mapped by drawing what the water did. The two solutions address the same problem from opposite ends.
And it fits everything else you see in Majuro. In a country where land is three per cent of the territory and the rest is water, it makes sense that even the map is made of waves.
