Between 1980 and 1987, the U.S. Department of the Interior funded a series of benthic studies of the continental shelf off south western Florida. The goal was to gather environmental information in order to make decisions about offshore oil leasing. One major study element was habitat mapping. Fourteen transects were surveyed geo- physically (side scan sonar, subbottom profiler) and visually (underwater video and still cameras), and the results were compiled in atlases showing the distribution of substratum types and visually distinct benthic communities. Rock outcrops were rarely seen and usually of low relief (< 1 m), but patches of reef-associated sessile epifauna such as sponges, hard corals, gorgonians, ascidians, and bryozoans occupied 31% of the seafloor surveyed. Most of the sessile epifauna were seen on hard bottom covered by a thin sand veneer, or on biogenic rubble layers (shell rubble, coralline algal nodules). A second major study element was benthic station sampling. Fifty-five stations were sampled from two to twelve times each, and over 1,500 species of epibiota and over 1,100 species of macroinfauna were identified. The species composition of both hard- and soft- bottom communities varied primarily in relation to water depth.