The wreck lay just 250 meters off the northeast coast of Pandanan Island, concealed beneath sand and mud under a coral reef overhang. Surveyors worked from 1993 to 1994 mapping the site before the Underwater Archaeology Division of the National Museum began formal excavation in 1995. What they found was a vessel roughly 25 to 30 meters long and six to eight meters wide, with a flat bottom suited for riverine as well as coastal waters. Only a quarter of the hull remained intact -- tropical sea worms had consumed the exposed wood, and strong currents had scattered the rest. But the cargo told the story. Chinese coins dated to the reign of the Yongle Emperor (1403-1424), blue-and-white porcelain from the Jingdezhen kilns, celadon ware from the Longquan kilns, stonewares from Fujian and Guangdong -- the ship was a floating inventory of 15th-century Asian commerce.

The diversity of the Pandanan ship's cargo reveals the complexity of maritime trade in the 15th-century South China Sea. Alongside the Chinese wares, archaeologists recovered blue-and-white porcelain from the Chu Dau kiln in northern Vietnam -- bowls, dishes, pots, jarlets, covered boxes, and water droppers. From central Vietnam's Go Sanh kiln in Binh Dinh Province came celadon saucers and dishes. Thailand contributed a large bowl with a fish design in iron pigment from the Sukhothai kiln and a black-brown glazed four-eared jar from the Noi River kiln. The metalwork told its own story: two small bronze cannons, five gongs, a lamp, a scale balance, a mirror, and approximately 60 iron cauldrons. Twenty-one grinding stones, likely used for honing sword and knife blades or processing food, suggested the ship carried practical goods alongside luxury wares. This was not a royal tribute vessel. It was a working merchant ship, loading cargo at multiple ports across Southeast Asia.

Among the most revealing artifacts were glass beads found inside Vietnamese stoneware jars -- small spheres in black and red that seemed, at first, to be minor curiosities. Physical analysis of 204 beads from the Pandanan site, comparing their diameter, perforation size, shape, and manufacture to 20 glass beads from Sungai Mas on the northwest coast of Malaysia, revealed that 85 percent of the Sungai Mas beads were identical matches. The conclusion reshaped understanding of the ship's route. For beads from Sungai Mas to reach the South China Sea and the Philippines, they had to cross the Malaysian peninsula, either through the Malacca Strait by sea or overland. The Pandanan ship likely traveled southward from China or Vietnam, stopping at the port of Patani or Singora on the Thai-Malay peninsula to load the beads and other trade goods, then continued to northern Borneo, Labuan, and through the Balabac Strait toward southern Palawan, where it sank.

The excavation itself was a feat of endurance. All work was done during daylight for safety and visibility. Divers excavated for 30-minute intervals at depth before ascending through an hour of decompression stops, starting at 15 meters and rising in three-meter increments, switching from air to oxygen for the final two stops. A total of 301 earthenware vessels and fragments were recovered, including cooking pots still blackened with soot from the ship's galley, three types of portable stoves for onboard cooking, and pouring vessels with polished bottoms. The site dates to a period when written records about the Philippines and Southeast Asia are nearly nonexistent, making the Pandanan wreck one of the most important archaeological windows into 15th-century life and commerce in the region. What a pearl diver found while looking for a lost basket of oysters turned out to be a time capsule from an era when the seas between China, Vietnam, Thailand, Malaysia, and the Philippines were connected by trade routes that no empire fully controlled.