The GPSMAP 420 features an ultra-bright 4” QVGA display and a built-in, satellite-enhanced worldwide basemap. The worldwide basemap on the 420 can be enhanced with the optional BlueChart® g2 Vision card, which provides high-resolution aerial reference photos for help navigating tricky harbors and channels — or locating spots like area marinas, fuel stops or restaurants. The g2 Vision plug-in data card also allows the GPSMAP 420 to graphically depict a true 3D “mariner’s eye” topside view or “fish eye” underwater navigation perspective. Experience super simple user interface for easy operation. With fewer buttons to push and fewer operational steps to navigate, the simplified menu format on the 420 makes it easy for you to see and select the data you want to access on-screen. Simplify navigation with Auto Guidance Optional g2 Vision auto guidance technology will help simplify your navigation.Auto Guidance searches all the chart features to suggest the best known charted route for navigation. Waterproof: IPX7.Where applicable, the sounder version, GPSMAP 420s, comes with a powerful dual frequency transducer that clearly paints depth contours, fish targets and structure whether you’re fishing in freshwater or off the coast. The 420 and 420s are also CANet™ compatible, so you can share sounder data with another chartplotter on your boat.