NEW YORK • Mr Wynand Hendrikse is a diamond diver. For 20 years, he has spent his days sailing off the western coast of South Africa, exploring a private offshore concession an hour south of the Namibia border.

His office is on a boat and his uniform is a wetsuit and fins. His mission is to scan the shallow sea floor for precious minerals. Almost every day that he spends in the water, he hauls up a pile of diamonds, which he then turns into bespoke pieces at his Stellenbosch design studio.

For hundreds of years, a rough marine system called the Benguela Current has provided a bounty of conflict-free diamonds to an area called the Angola-Benguela Front.

The diamonds, which originated deep in the earth, were swept to the ocean floor over millions of years after circulating through African waterways along various rivers and deltas. That is where they encounter the strong Benguela waters, which can carry only the heaviest stones, collecting a glittering trail for humans to recover.

You can, too, as long as you have a Padi Open Water certificate and US$16,000 (S$21,600) to spare.

Earlier this year, Mr Hendrikse founded Benguela Diamond safaris and now offers day-long trips for groups of two to six guests. The programme is available primarily through Cape Town's ritzy Ellerman House, a 15-room Cape Edwardian mansion that once belonged to shipping magnates John and Lady Ellerman, though it is also being offered as an add-on to itineraries with the high-end travel agency Epic Road.

The experience begins with a limousine ride to a private charter flight for the roughly one-hour journey to the colourful coastal town of Port Nolloth, where Mr Hendrikse maintains a beachside villa. That is where you will meet your dive masters, share a catered breakfast and learn about what the day has in store.

Mr Hendrikse's small, industrial- feeling boat is built to withstand the choppy waters that make this offshore concession so rich in shiny stuff. "The waters in most areas along this front are too harsh for travellers to have this experience," said Epic Road co-founder Mark Lakin. "Port Nolloth is the safest option."

The underwater diamond-hunting process for guests is all about observation. While you look for glassy stones, the master divers do the more laborious part, manoeuvring giant suction pipes to pump up promising gravel.

The largest chunks get separated out and brought back to the deck of your ship, where you can "jig" them on a vibrating pan to reveal your catch: not just diamonds, but sometimes garnets and bright green olivines as well.

The process, explained Mr Hendrikse, is like panning for gold. And according to a spokesman, guests are "almost 100 per cent guaranteed to find a diamond".

Back on dry land, you will huddle with an expert grader, who can assess your stones and help you decide which ones to get cut, polished and set into a custom piece.

The whole process of getting a stone from the sea floor to setting takes three days.

While everything from the private flight to the meals is included in the experience, local regulations (that is taxes, concession fees) require you to pay for whatever gem you want to keep.

BLOOMBERG