Uninterpreted high-resolution "boomer" seismic data show limited penetration and a change from more continuous sediment cover nearshore to a more discontinuous distribution of sand waves offshore. Poor acoustic contrast between the Holocene sediment cover and the underlying pre-Quaternary bedrock is attributed, in part, to the weathered nature of the Neogene limestone. Some deformation of the pre-Quaternary bedrock is attributed to karst processes at depth. The modern sediment cover is typically less than 2 m thick, corresponding with the higher-relief portions of the sand waves and ridges seen here.