High Quality Content by WIKIPEDIA articles! Sailing Directions is a 42-volume American navigation publication published by the National Geospatial-Intelligence Agency (NGA). Sailing Directions consists of 37 Enroute volumes, 4 Planning Guide volumes, and 1 volume combining both types. Planning Guides describe general features of ocean basins and country-specific information such as firing areas, pilotage requirements, regulations, search and rescue information, ship reporting systems, and time zones, to name a few; Enroutes describe features of coastlines, ports, and harbors.