Brushing the last white grains of sand away from a heart-shaped wooden box 39.5 meters (130 feet) beneath the azure surface of the Red Sea, I suddenly realized this was not a box at all, but a gigantic seed. It was, in fact, the world's largest seed — a bi-lobed coconut, or coco de mer, from the Seychelles Islands, thousands of kilometers from my excavation at Sadana Island. How this 25-kilogram (55-pound) monster came to be at the foot of a coral reef off the coast of Egypt is part of the story of the global economy and the complex web of trade routes in the second half of the eighteenth century.

In 1994, I led a team from the Institute of Nautical Archaeology on its first project in Egypt. With the help of local sport divers, we pinpointed more than a dozen anchors or scatters of pottery along the Red Sea coast and visited several shipwrecks.

We decided to focus on the wreck at Sadana Island — a small coral reef a few hundred meters off the Egyptian coast — in part because it was being routinely looted by unscrupulous divers. In addition to providing underwater experience for Egyptian students and archaeologists, the project led to the creation of the Alexandria Conservation Laboratory for Submerged Antiquities, a joint project of Egypt's Supreme Council of Antiquities and INA under the leadership of Doug Haldane and Howard Wellman.

But for me, the primary appeal of the site lay in its paradox: so close to our own time, yet so remote from our knowledge that there was little we could say with confidence about it.