Figure 3. A digital elevation model (DEM) produced from swath (interferometric, multibeam, and lidar; collected within the red polygon) and single-beam (collected outside the red polygon) bathymetric data gridded at a 10-meter-per-pixel horizontal resolution (table 1). Black polygons indicate areas of figures 21 and 22. Depth is referenced to the North American Vertical Datum of 1988. The locations of Lucas (L), Middle Ground (MG), L'Hommedieu (LH), Hedge Fence (HF), and Squash Meadow (SM) Shoals are also indicated.