Albert Mandobe, right, helping Jaco Boshoff scan beneath the sands seeking traces of the Meermin, a Dutch ship with 147 slaves on board.
At Struis Bay, a slave ship may lie under the sand, a rare discovery.
STRUIS BAY, South Africa, Aug. 20 - After years of painstaking research and sophisticated surveys, Jaco Boshoff may be on the verge of a nearly unheard-of discovery: the wreck of a Dutch slave ship that broke apart 239 years ago on this forbidding, windswept coast after a violent revolt by the slaves.On the other hand, he may have discovered a wire fence covered with beach sand.
Mr. Boshoff, a 39-year-old marine archaeologist with the government-run Iziko Museums, will not find out until he starts digging on this deserted beach on Africa's southernmost point, probably later this year.
After three years of surveys with sensitive magnetometers, he knows, at least, where to look: at a clutch of magnetic abnormalities, three beneath the beach and one beneath the surf, near the mouth of the Heuningries River, where the 450-ton slave ship, the Meermin, ran aground in 1766.
If he is right, it will be a find for the history books - especially if he recovers shackles, spears and iron guns that shed light on how 147 Malagasy slaves seized their captors' vessel, only to be recaptured.
Though European nations shipped millions of slaves from Africa over four centuries, archaeologists estimate that fewer than 10 slave shipwrecks have been found worldwide.
If he is wrong, Mr. Boshoff said in an interview, "I will have a lot of explaining to do."
He will, however, have an excuse. Historical records indicate that at least 30 ships have run aground in the treacherous waters off Struis Bay, the earliest of them in 1673.
Although Mr. Boshoff says he believes beyond doubt that remains of a ship are buried on this beach - the jagged timbers of a wreck are sometimes uncovered during September's spring tides - there is always the prospect that his surveys have found the wrong one.
"Finding shipwrecks is just so difficult in the first place," said Madeleine Burnside, the author of "Spirits of the Passage," a book on the slave trade, and executive director of the Mel Fisher Maritime Heritage Society in Key West, Fla. "Usually - not always - they are located by accident."
Other slave-ship finds have produced compelling historical evidence of both the brutality and the lucrative nature of the slave trade. From the British ship Henrietta Marie, the only slave ship ever excavated in American waters, archeologists recovered 80 sets of iron shackles, cast-iron cannons and pewter mugs.
The Henrietta Marie, discovered in 1972, was partly reconstructed and turned into a popular museum exhibit that toured the United States. Now housed at the Maritime Heritage Society's museum, the exhibit depicts conditions aboard for 190 African slaves who were sold in Jamaica just before the vessel sank 35 miles off Key West around 1700.
Archaeologists who excavated the Henrietta Marie were lucky to find the ship's bell engraved with its name. For Mr. Boshoff, who at every opportunity tramps about on this beach with a global positioning device, a measuring wheel and wooden marking poles, identifying a wreck may be more of challenge.
His best hope of proving that any find is in fact the Meermin, he said, will be to unearth one of the Malagasy spears that records show were carried aboard the ship.
The ship's final voyage is well documented in letters and court records in archives in Cape Town, which are being organized electronically by Andrew Alexander, a University of Cape Town history student who is working with Mr. Boshoff. The documents tell a story rife with folly, trickery, men tossed overboard, bottled messages, rescue ships gone awry and captives-turned-captors-turned-captives once more.
In the end, half of the 60-member Dutch crew and perhaps dozens of slaves were killed. The surviving crew went down in ignominy for losing their ship; the Malagasy slaves met bondage and servitude.
The Dutch East India Company dispatched the three-masted Meermin from Cape Town in December 1765 to buy slaves on the west coast of Madagascar, nearly 1,700 miles away. The growing Dutch settlement at Cape Town relied on slave labor, and the warring tribes on Madagascar were known to trade their captives to European merchants for guns and goods.