There is also a barometric altimeter to track altitude by measuring pressure changes, which can also be used to track weather conditions. The IPX7 case is waterproof, and even floats if dropped in water. The Garmin GPSMAP 76S is preloaded with a basemap of principle cities, interstates (including exits), highways and roads as well as marine navigation aids, including lights, buoys, sound signals and day beacons. There is 24 MB of internal memory allowing you to store detailed maps from a variety of optional MapSource products. For boating, hunting or fishing, the built-in celestial data gives tide information, sunrise/sunset times and a hunting and fishing calendar.
