Bathymetry is a measure of the water depth relative to sea level. As a result, elevations or depressions of the sea floor can be readily detected. Here are samples of ocean floor bathymetry at two of the proposed sites (lease blocks VK906 (shown here) and VK826). Preliminary data from both sites suggest that corals are present. Differences in sea-floor elevation can be readily seen. Note that the elevation scales are different between the two images.