New side-scan sonar images that are free from scale distortions have been acquired from an area of the Mississippi Delta, where a variety of subaqueous landslides are forming. Collapse depressions, diapiric intrusions, elongate sinuous and merging channels floored with chaotic blocks, and prominent parallel and subparallel scarps result from various types of subaqueous mass-movement processes. Scale-true, overlapping adjacent sonographs, combined with accurate offshore navigation, have yielded the first mosaics of the sea-floor morphology over a 70-km2 area. These mosaics can be used to infer a considerable number of associations in morphology, forcing mechanisms, and spatial internal characteristics. The new side-scan sonar method offers considerable potential for accurate remapping and assessment of active submarine landslides.