Recent surface sediments from the continental shelf in the vicinity of the Howick Group have been analysed to determine their textural, chemical and skeletal composition. There is a decrease in terrigenous particle size from quartz sand in the nearshore area to mud offshore. Carbonate particle size decreases from gravel to mud moving away from the reef. Multivariate statistical analysis of grain size data has determined the influence of various sources. Q-mode cluster and factor analysis distinguished four sediment types and indicated that three factors are responsible for 94% of the textural variation. R-mode cluster analysis showed three distinct size populations. They result from intermixing of material from different sources and do not necessarily reflect distinct modes of transportation. The distribution of the textural sediment types displays concentric elliptical patterns around each platform reef in a zone approximately 2 km wide, within which there is a size gradient from coarse sand and gravel near the windward reef edge to fine sand near the leeward margin.