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Navigation chartNavigation chart © The Trustees of the British Museum

Navigation chart

Marshall Islands, Micronesia. 19th to early 20th century C.E. Wood and fiber.

Curator Note

"GPS of the ancients. This is not a literal map of land, but a map of water physics. It maps the swells and wave patterns caused by islands. Navigators (ri-metos) memorized these on land by feeling the sticks, then navigated the open ocean by feeling the water disruption under their canoe."

Form

  • Material: Coconut midribs (sticks) tied together with fiber.
  • Shells: Cowrie shells attached to represent island positions.
  • Structure: Abstract geometric grid/lattice.
  • Types: Mattang (training), Meddo (sub-regions), Rebbelib (large area).
  • Durability: Lightweight and buoyant.

Function

  • Educational Tool: Used on land to teach novices how to read waves.
  • Mnemonic Device: Used by masters to refresh memory before a voyage.
  • Not taken to sea: It was too fragile and unnecessary once memorized.
  • Survival: Critical for finding tiny atolls in the vast Pacific.
  • Secret Knowledge: Navigation was a guarded secret of the chiefly class.

Content

  • Stick Intersections: Represent the interaction of different wave swells.
  • Curved sticks: Represent the way waves "bend" (refract/diffract) around islands.
  • Shells: Represent islands (but relative position, not exact GPS coords).
  • Diagonal lines: Indicate wind and swell directions.
  • Empty space: The open ocean.

Context

  • Marshall Islands: Low-lying atolls hard to see until close; wave reading is essential.
  • Wave Piloting: Reading the "reflection" of waves off land masses.
  • Oral Tradition: Knowledge passed father to son.
  • Technology shift: Use declined with European charts/GPS.
  • Identity: Symbol of Marshallese ingenuity.