Dispersal patterns, based upon the frequency distribution of rock types in the submarine gravels of Foveaux Strait, indicate a connection between the gravels and the present terrestrial drainage systems to the north and south of the Strait. It is inferred that the submarine gravels were initially deposited as fluviatile sediments during a former period of low sea-level. It is further suggested that the significant factor regulating the proportions of the various rock types was not distance from the periphery of the present marine environment or the proximity or relief of the source areas. More important were the actual sizes of the water catchment and source areas on opposite sides of the Strait.