Deep foliage, nor canyons faze the rugged eTrex Vista HCx. Its high-sensitivity receiver holds a GPS signal in the toughest environments. The eTrex Vista HCx locates your position quickly and precisely and maintains its GPS location even in heavy cover and deep canyons. The advantage is clear - whether youâ€™re in deep woods or just near tall buildings and trees, you can count on Vista HCx to help you find your way when you need it the most. Adding maps is easier than ever with Vista HCxs microSD card slot. Conveniently plug in optional preloaded microSD cards with MapSource data for your land and sea excursions. Just insert a MapSource card with detailed street maps, and Vista HCx provides turn-by-turn directions to your destination. The card slot is located inside the waterproof battery compartment, so you dont have to worry about getting it wet.