The world's biggest floating diamond processing vessel will set sail for the first time within three weeks and should be in position off Namibia before Christmas, the Namibian Minerals Corporation (NAMCO) said. "This is the biggest offshore diamond processing plant in the world," NAMCO chairman Alastair Holberton told reporters on a tour of the ship in Cape Town harbor. "We expect that in its first work up year in operation it will harvest 200,000 carats of diamonds worth about $30 million," he added. Geologists estimate that up to three billion carats of diamonds lie off the Namibian and South African coasts. NAMCO has four mining vessels, including the new vessel, MV Ya Toivo, to comb the sea bed. Holberton said the latest project had cost NAMCO 200 million rand ($25.71 million).