The U.S. Geological Survey, in cooperation with the National Oceanic and Atmospheric Administration and the Connecticut Department of Environmental Protection, has produced detailed geologic maps of the sea floor in Long Island Sound. These studies have built upon cooperative research with the State of Connecticut that was initiated in 1982. This research program is currently studying sea-floor sediment distribution, processes that control sediment distribution, nearshore environmental concerns, and the relation of benthic community structures to the sea-floor geology. Detailed maps of the sea floor are needed to aid in interpretation of the sea-floor geology. Therefore, sidescan-sonar data have been collected in areas of interest. Although these mosaics from NOAA surveys H11043, H11044, and H11045 in north-central Long Island Sound have been interpreted in prior reports, we have enhanced these three mosaics in order to minimize tonal artifacts created by the mismatching of backscatter in adjacent track lines. The enhanced mosaics provide a clearer image of the sea-floor geology.