This report presents the results of visual and photographic underwater surveys from the shoreline to a depth of 600 feet along selectedi routes off the eastern coast of Andros Island, Bahamas. Additional oceanographic and meteorological data are included which were obtained during previous surveys. This is the U. S. Naval Oceanographic Office's first survey utilizing SCUBA equipped divers and submersibles and represents a further expansion cf our data collection and survey capabilities to provide a more lucid presentation of ocean environmental characteristics Tie survey was performed to provide information applicable to thc installation of submarine cables in support of the U,, S. Navy's Atlantic Undersea Test and Evaluation Ceater.

A visual and photographic survey of the shore and ocean bottom to 600 feet (100 fathoms) depth was performed off selected sites on the east coast of Andros Island, Bahamas. Climatology and oceanographic conditions are also presented. Survey methods employed both SCUBA divers and a manned submersible (Perry Cubmarine PC3-B) to provide direct visual observation and measurement of bottom features. The Andros shoreline was observed to vary considerably in morphology and composition: barrierreef development ranges from well-developed to virtually non-existent from north to south along Andros Island. A marginal escarpment commencing offshore between 14 and 16 fathoms was observed to descend almost vertically to 100 fathoms. Various morphologic features of the escarpment suggest a lowering of sea level and subsequent subaerial and intertidal erosive processes which have been active in the recent geologic past.

Graphic illustration by a scientifically trained artist provides a panoramic view of the sea floor unobtainable directly by photography. Detailed photographs, direct observations, and field sketches are combined to produce a photographically documented hypsographic reconstruction of the sea floor. Dry submersible or diver traverses show only a sequence of closeup photographs because of the visibility limitations presented by the ocean environment. At present the large scale aspects of the topography are best developed from direct observations. The underwater photographs arranged in traverse sequence serve to refresh the memory and provide topographic, geologic, and biologic detail. The resulting detailed illustration gives a three dimensional composite panorama of the sea floor. This combined artist-photographic technique has been applied to: submarine cable routing, habitat emplacement, and geological and biological reconnaissance.