Please add a Rugosity Tool (for planar and geographic/geodesic analysis) to ArcGIS (e.g., Spatial Analyst extension). This tool is available via the freely available Benthic Terrain Modeler (
http://www.csc.noaa.gov/digitalcoast/tools/btm) but that application is not being migrated to ArcGIS 10.x. The rugosity tool is apparently available in the new ArcGIS for Maritime: Bathymetry special extension but this is an additional extension with a license fee. The rugosity tool has applications beyond bathymetric environments (e.g., topographic) so it would seem this tool should be more widely available in a mainstream extension to ArcGIS. The tool is available here as an example of how to implement:
http://www.jennessent.com/arcgis/surface_area.htm