NTBA performed a hydrographic survey of an area of the Ouachita River as a sub-consultant. The survey determined the river bottom elevations at a predetermined line in order to plan a directional drill for a new fiber optic line under the river. The survey consisted of running a range line at predetermined stations over the water and on the banks. Survey included the establishment of a pre-determined range line, utilizing USGS benchmark, determining water elevation, performing fathometer bar check to ensure correct Speed of Sound, running and charting predetermined range line, obtaining marks at pre-determined distances along the range. NTBA also prepared sketches of the water body surveyed, reduced chart data from depths to elevations, prepared a data chart with the depths, elevations, and locations of the data obtained, and a written report on each survey noting field conditions and findings.