In excess of 50 km of side scan sonar records were obtained with an EG&G AS600 system on the extensive sand body offshore of the straight, N/S, sandy, eastern shore of Lake Ontario. The records disclose a sand sheet which laps on to bedrock and till(?). These records are part of an extensive geophysical and sedimentologic dataset accumulated during the Eastern Lake Ontario Sand Transport Study(ELOSTS)to provide a basis for development of a shoreline management plan. The side scan records demonstrate a patchy sand distribution at the south end of the sand sheet. At about the midpoint of the N/S shoreline, the sand sheet is broken by isolated exposures of till(?). Further north, sand is patchy on bedrock and at the north end of the surveyed lake bottom, bedrock is fully exposed. Wave-generated currents moving this well sorted sand generate low-relief bedforms both parallel to and perpendicular to shore. As examples, broad,low-relief, vaguely-defined ripples or small dunes are developed at several locations. Crests of these bedforms appear to be parallel to shore. Other ripples developed in coarse sand occur in small patches on the few till exposures. Their crests are perpendicular to the shore. Flute-shaped patches of what appear to be zebra mussels are developed on the sand sheet toward its north end. Their arrangement suggests offshore current flow.