Swells

"I have heard from several sources that the most sensitive balance [to feel the swells] was a man's testicles GLOSSARY testicles - male genitals ...”
From Captain Ward in Lewis, D. (1972).

“We know from German ethnographers that there were women professors In Micronesian voyaging schools. We also know that there were at least 2 women wayfinders in the Santa Cruz Islands. One of them, Hoakena, died around WWII. She bought a Vaka from Basil Tevake. Another, Joann Hahala, died in 2011.”
Marianne “Mimi” George

Unlike stars, which sometimes can’t be seen, swells GLOSSARY swells - rolling waves caused by trade winds and storms are always there and keep their direction for many days. This makes them very useful for navigation. A navigator relates their direction to the star positions.

To teach children about swells, a teacher lies students on their back in the sea so that they can feel the swells. A wayfinder cannot depend on sight at night or when visibility is bad.

The wayfinder knows how the vaka should move on the swell if it is heading in the right direction. For example, if its course is straight into a swell, the hull goes up when the swell meets it and down when the swell passes under it. If the vaka goes off course, it starts to roll. The point where the swell meets the hull changes too, and the wayfinder can see and feel this. A wayfinder notices the shape of the swell to tell the direction and strength of the current GLOSSARY current - the directional flow of the sea underneath. Currents can affect the course and speed of the vaka.

In the Marshall Islands, swells, currents, and winds are used more than stars for wayfinding. There, the two parallel chains of the Marshall Islands stretch across the face of the main swell, making the swell patterns similar between the two chains. Wayfinders will always feel or see the swells, but the stars may be hidden by clouds. [See figure 1].

“With Tevake, in Santa Cruz […] we had three wave patterns running […] it started to rain, and the wind started to shift. Tevake stood […] feeling this very faint lift of the swell coming […] from the north-east, and he steered by that for 8 hours, standing sopping wet in his lavalava […] So this is navigating by the swells, by feel …”
From David Lewis in Bader, H. and McCurdy, P., eds (1999).

What Causes Swells?
Swells are caused by big winds many kilometres away. They feel different from local waves, which are caused by local winds. Usually, local waves are shorter and steeper GLOSSARY steeper - more vertical, upright , and if they are coming ashore, or if the wind is strong enough, they break at the top. Swells are wider apart and have a rolling motion. There are often waves on top of swells. Even when two or three or more swells are mixed with local waves, a wayfinder can separate them and use the right one to steer by… or use more than one swell and keep the vaka at the same angle to any or all of them at the same time. Wayfinders know which swells are most reliable.

Marshall Islands Navigation
Marshallese wayfinders have studied how waves diffract GLOSSARY diffract - the bending of waves around obstacles in their path around and reflect GLOSSARY reflect - bounce islands and then interfere with one another. They show how this happens in mattang stick charts, and they represent the wave patterns around specific islands in rebbellith and meddo stick charts. These charts are used for teaching. The Marshallese have many words to describe the currents too – for example, jukae (first area of currents – nearest an island), dibukae (second area of currents), and jejelatae (third area of currents – furthest from the island).

Interrupted swells are especially useful for finding land. Marshallese navigators have a highly developed system of knowledge about this.

Click here for more information about interrupted swells.

Satawalese wayfinder Mau Piailug talks to his crew about the swells

Satawalese wayfinder Mau Piailug

“Piailug first learned them as part of his grandfather’s crew. The old man showed Mau how to read the swells. There are eight distinct swells. Each one is connected to a specific position of a star on the star compass. But swells tell more than what course you’re on. If you can read their shapes, you can know the strength and direction of the current running beneath them. If you don’t know what the current’s doing, you can steer a perfect course and still become lost.”
From The Last Wayfinder © INCA 1989. Directed by Andre Singer.

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