The Chart Correction Template includes stencils for Region A & B IALA Maritime Buoyage symbols that are required for updating and correcting nautical charts. Keeping charts updated ensures the safety of your crew and vessel. Designed for use with a fine-line pen, corrections to nautical charts can be made neatly and quickly with this simple-to-use stencil. These corrections then become a permanent part of the chart. Corrections should be made in ink so they will not be accidentally erased when you are plotting courses on the chart. Please reference US Nautical Chart No. 1 or UK Admiralty Chart 5011 for assistance with symbol identification. This is an exact replica of the Chart Correction Template formerly prepared and published by the National Geospatial Intelligence Agency (NGA).