It has a barometric altimeter to precisely track the user's topographical location; a 3-axis compass with electronic tilt compensations; and wireless device-to-device sharing of data, with other eTrex 30 or compatible devices. This unit has preloaded basemaps, expandable memory for topographical or nautical maps, as well as a colour display. Like the 10 and 20 models below it, the 30 has improved battery life over older eTrex handhelds, and lasts for about 25 hours of usage.
