Maptech Waterproof Chartbooks Casco Bay To Camden . These easy-to-use compact chart books are ideal for day sailors fishing boats and trailer boats. They measure 12 x 17 24 x 17 when open and are made of waterproof tear-resistant synthetic paper that will withstand the elements. GPS Ready New features make Waterproof Chartbooks easy to use with your GPS. Most charts include one-minute lat.long. grids to make vessel positioning a breeze and major navigation aids are identified with named GPS waypoints. Small and Large-Scale Charts Waterproof Chartbooks include small-scale wide area charts as well as large-scale detailed charts of harbors and approaches. The Chart Page Index on the front cover and Go-To page numbers make it simple to quickly find the chart you want. Pre-Plotted Courses Maptechs navigation editors add magnetic courses between major navigation aids with distances in nautical miles. Chartbooks are also designed to help you do the calculations yourself. Each page includes a Compass Rose with annual increase in variation and complete scale information.