During a dredging trial conducted by the licensee in the Gulf on 9-10/11/1976, using the dredging vessel "Andrew Wilson" owned by the SA Board of Marine and Harbours, some 200 tonnes of shell were recovered from the open seabed in seven locations where the water depth varied from 20.4 to 22.4 m depth. A grab was used to raise ~ 30 t/hour of material, which consisted mostly of fine broken shell fragments, with a few larger, entire shells and also a proportion of lime-sand cemented shell conglomerate. Leaching tests indicated the possibility of removing excess chloride by heap leaching using rainfall percolation, if assisted by regular addition of mains water. A 500 kg sample of the shell was sent to Loesche KG in Dusseldorf, West Germany for testing to determine the practicability of grinding the material to the required size in a ring roller mill. Quotes were obtained from commercial dredging companies for proposed production scale operations. But when these were considered in the light of grindability data provided from overseas, they indicated that the shell material would not be economic for the licensee to use as intended for feeding into its new dry process kiln plant at the Birkenhead cement works.