Figure 23. Detailed planar view of the sun-illuminated bathymetry from the combined National Oceanic and Atmospheric Administration surveys in Rhode Island and Block Island Sounds showing large transverse sand waves on a shoal west of Block Channel (fig. 1). Note that most of the sand-waves are symmetrical. Location of view is shown in figure 11. Warmer colors denote shallower areas; cooler colors denote deeper areas. Depth key is shown in figure 9.