A new CGTN documentary, Genglubu: Charting the South China Sea, explores the story of the Genglubu, a handwritten navigation manual that guided generations of Hainan fishermen across the South China Sea long before GPS, weather forecasts, or satellite navigation. The documentary sheds light on a little-known chapter of maritime history, tracing how fishermen from Tanmen, Hainan Province, used these manuals to record routes, compass bearings, and sailing distances, navigating reefs, islands, and open seas. The Genglubu, passed down through generations, contains routes that extend beyond the South China Sea to Singapore, Malacca, and Indonesia, showing that Hainan fishermen also played a role in regional maritime trade, according to Zhao Jueqi of the China (Hainan) Museum of the South China Sea.
The documentary features veteran fishing boat captains like Wang Shitao, who first went to sea at age nine and survived two typhoons that killed all other crew members. Reflecting on decades spent sailing the South China Sea, he said: "I love the South China Sea. I hate it. I miss it." Another captain, Wang Shubao, noted the sea's dangers: "Children and brothers should never sail on the same boat." The Genglubu appears as a secret code to outsiders; a single line of fourteen Chinese characters can contain an entire sea route, including departure point, direction, destination, distance, and estimated sailing time. Some manuscripts also contain mountain-and-water charts combining coastline sketches with compass bearings and water depth, helping sailors identify islands and determine their position at sea.
International law scholar Anthony Carty noted that American and British navigational records identify Chinese as heavily engaged in fishing on these islands and other economic activities. The documentary challenges the assumption that the Genglubu was only about the South China Sea, revealing routes to Singapore, Malacca, and Indonesia. Today, while satellites and weather stations have transformed navigation, the purpose remains the same: helping sailors travel safely and return home. The documentary traces a maritime tradition shaped by ordinary people, forming part of the shared maritime heritage of Asia. According to Xin Lixue, curator of the China (Hainan) Museum of the South China Sea, "Generation after generation, Hainan fishermen rode the waves – not to rule the sea, but to make their living from it."
