For boaters and watersports enthusiasts who want to run with the best, the rugged GPSMAP 78 features crisp color mapping, high-sensitivity receiver, new molded rubber side grips, plus a microSD card slot for loading additional maps. And it floats!. GPSMAP 78 comes with built-in worldwide basemap, so you can navigate anywhere with ease. And, like the rest of the 78-series, the 78 is IPX7 waterproof and even floats in water. With its high-sensitivity, WAAS-enabled GPS receiver and HotFix satellite prediction, GPSMAP 78 locates your position quickly and precisely and maintains its GPS location even in heavy cover and deep canyons. The advantage is clear - whether you're in deep woods or just near tall buildings and trees, you can count on GPSMAP 78 to help you find your way when you need it the most.