Pacific seafarers developed indigenous navigational techniques to voyage between islands. In the Marshall Islands, navigators remotely sense land by detecting how islands disrupt swells. A recent project to revitalize Marshallese voyaging aimed to understand the science of wave navigation. Local wave concepts are described based on anthropological fieldwork with surviving navigators, including interviews and experience sailing with them. The wave transformation processes that give rise to these patterns are examined using navigators’ demonstrations at sea, wave buoy measurements, satellite imagery, and wave model simulations. The scientific data account for one signal used by navigators to remotely detect land. Crossing wave trains extend tens of kilometers in the lees of islands, which can be simulated as refraction of the easterly trade wind swell. Navigators identified a superposition of incident swells with reflected waves 40 km upstream of islands. These reflected waves were too weak to be detected by the wave buoy, but they are conceptualized similarly within indigenous and scientific frameworks. Navigators described another pattern as a wayfaring link between distant atolls. This pattern does not clearly relate to a wave transformation process, suggesting that Marshallese navigators also use concepts of the ocean that do not easily translate into oceanographic terms.

Genz, J., J. Aucan, M. Merrifield, B. Finney, K. Joel, and A. Kelen. 2009. Wave navigation in the Marshall Islands: Comparing indigenous and Western scientific knowledge of the ocean. Oceanography 22(2):234–245, https://doi.org/10.5670/oceanog.2009.52.

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