Navigation Features   Waypoints/icons: 500 with name and graphic symbol, 10 nearest (automatic), 10 proximity Routes: 50 reversible routes with up to 50 points each, plus MOB and TracBack® modes Tracks: Automatic track log; 10 saved tracks let you retrace your path in both directions Trip computer: Current speed, average speed, resettable max. speed, trip timer and trip distance Alarms: Anchor drag, approach and arrival, off-course, proximity waypoint, shallow water and deep water Tables: Built-in celestial tables for best times to fish and hunt, sun and moon rise, set and location Map datums: More than 100 plus user datum Position format: Lat/Lon, UTM/UPS, Maidenhead, MGRS, Loran TDs and other grids, including user grid    GPS Performance   Receiver: WAAS-enabled, 12 parallel channel GPS receiver continuously tracks and uses up to 12 satellites to compute and update your position Acquisition times: Warm: Approximately 15 seconds Cold: Approximately 45 seconds AutoLocate®: Approximately 2 minutes Update rate: 1/second, continuous GPS accuracy: Position: < 15 meters, 95% typical* Velocity: 0.05 meter/sec steady state WAAS accuracy: Position: < 3 meters, 95% typical* Velocity: 0.05 meter/sec steady state Dynamics: 6 g's Interfaces: RS232 with NMEA 0183, RTCM 104 DGPS data format and proprietary Garmin® Antenna: Built-in quadrifilar, with external antenna connection (MCX) Differential: DGPS (USCG and WAAS capable)    Power   Source: Two "AA" batteries (not included) Battery Life: Up to 16 hours    Physical   Size: 2.7"W x 6.2"H x 1.2"D (6.9 x 15.7 x 3.0 cm) Weight: 7.7 ounces Display: 1.6"W x 2.2"H (4.1 x 5.6 cm) 180 x 240 pixels, high-contrast FSTN with bright backlighting Case: Fully gasketed, high-impact plastic alloy, waterproof to IEC 529 IPX7 standards Temperature range: 5°F to 158°F (-15°C to 70°C) User data storage: Indefinite, no memory battery required