Traditional Western cartography relies heavily on static, visual landmarks and astronomical positioning to conquer the seas. This reliance created a massive historical blind spot regarding the indigenous seafarers of the Pacific, who successfully navigated millions of square miles of featureless ocean without a single compass or astrolabe. Their method did not map the stars; it mapped the water itself. Abyssal Navigation explores the astonishing geotechnical genius of Polynesian hydrography. Ancient wayfinders constructed intricate, abstract grids out of palm ribs and cowrie shells to physically model the refraction of deep-ocean swells bouncing off distant, invisible islands. These stick-charts were not maps to be read, but kinetic memory devices meant to train the navigator's body to feel microscopic shifts in the ocean's kinetic energy. Unearth the brilliant fluid dynamics understood by prehistoric mariners. Discover how these indigenous engineers deciphered the chaotic interference patterns of the sea, utilizing tactile hydrography to effortlessly connect an empire scattered across the largest and most volatile body of water on Earth.