In coastal environments, elevation is perhaps the most fundamental and important variable that determines vulnerability. Accurate high-resolution digital elevation models (DEMs) that show both land and submerged topography (bathymetry) are key in coastal wetlands mapping and monitoring, storm surge and sea-level rise modeling, benthic habitat mapping, coral reef ecosystem mapping, and a host of related activities. A special issue of the Journal of Coastal Research titled "Advances in Topobathymetric Mapping, Models, and Applications" provides a broad array of recent research findings on data, processing methods, applications, and physical processes that are critical for increased understanding of the dynamic coastal environment. The 17 papers presented in this issue offer current information for coastal zone resource managers and provide the impetus for future research and advances in data, methods, models, and applications for the changing coastal environment. The authors in the special issue include 16 researchers and technical staff members from several USGS science centers. The issue is available online at http://www.jcronline.org/toc/coas//76. For more information, contact Dean Gesch at firstname.lastname@example.org or 605-594-6055.