An English East Indiaman on her way to Surat on the west coast of India, the Joanna separated from her convoy and sank in rough seas on a reef off the southernmost tip of South Africa on June 8, 1682, sending 10 people to their death. Eventually, 104 survivors reached the Dutch colony of Cape Town, from which a salvage party was soon dispatched. The Joanna’s cargo consisted of 70 chests of silver coins, of which the salvage party reported having recovered only about 28,000 guilders’ worth. In 1982 the wreck was re-discovered by a group of South African divers led by Gavin Clackworthy, who brought up silver ingots (discs) and over 23,000 silver cobs, most of them Mexican 4 and 8 reales of Charles II in generally low grade, but a few showing bold, formerly very rare dates 1679-1681. Over the past two decades these cobs have entered the market from both private dealers and auctions, but always in relatively small quantities at a time. Almost all the coins are in very worn condition, usually thin and nearly featureless, but without the heavy encrustation and pitting that characterize Caribbean finds.