Underwater surveys off the coast of Luzon have identified a series of submerged workshops and cargo spills that delineate a 3,000-year-old maritime trade route between the Philippines and the Ryukyu Archipelago. The network, dubbed the "Jade and Tortoise-Shell Seaway," specialized in the exchange of nephrite jade tools for ornamental tortoise shells and red-slipped pottery.
Using multi-beam sonar and AI-driven bathymetry, the team located three distinct wreck sites containing high concentrations of worked jade. This finding suggests that Austronesian navigators had mastered complex open-ocean crossings far earlier than previously thought, establishing a proto-globalized economy across the Philippine Sea during the Bronze Age.