Preliminary probing of the sunken vessel - a 17th century Dutch ship - has already yielded 25 complete Chinese porcelain vases, hundreds of fragments of Chinese, Japanese and Persian porcelain, a fist-sized chunk of Oriental amber, Ceylonese cowrie shells for bartering, various hardwoods and quantities of cinnamon, clothes, pepper and the colour dye indigo.
Identification and dating of the different types of porcelain is being carried out by art historians at the Victoria and Albert Museum, London, and the Ashmolean Museum in Oxford.
The cargo is in the wreck of a Dutch East Indiaman - the Oosterlande - which sank in a storm 300 yards off Cape Town on 24 May 1697. There were only two survivors.
About three-quarters of the 125 ft by 33 ft (38m by 10m) ship remains buried in gravel and sand in only 15 ft of water.
The excavations, directed by Dr Bruno Werz of the University of Cape Town, will shed light on 17th century international trade, and especially on the activities of the Dutch East India Company.
Only one other fully laden Dutch East Indiaman - a vessel off Gabon, West Africa - has been archaeologically excavated.
The wreck is providing the first archaeological evidence of the illegal private trade which East Indiamen captains used to engage in - strictly against the wishes of their employers. Some captains actually built an extra cabin to accommodate their illicit trade goods - including porcelain.
The Dutch East India Company, founded in 1602, built the Oosterlande in 1684 in the Dutch town of Middelburg.
On its last voyage, it sailed from Flushing via the Cape Verde islands and Cape Town to Batavia (modern Jakarta) in Indonesia and then via Persia and Ceylon (Sri Lanka) to Cape Town.
The Oosterlande appears to have been a jinxed vessel. In the late 1680s, dozens of crew members perished when disease swept the ship - and in the early 1690s an unfortunate sailor was paralysed after being hit on the head by a meteorite.
The launch this month of a full excavation of the Oosterlande follows months of research at the Dutch state archives in The Hague and in local archives in Cape Town.
Rose Kerr, curator of the Victoria and Albert Museum's Far Eastern Collections, said the Chinese, Japanese and Persian porcelain being brought up from the wreck was of immense importance because it will for the first time help scholars to correlate the dates of porcelain production in the Orient and Middle East.