Garmin Marine 73H handheld GPS navigator has high-sensitivity GPS marks, 1,000 waypoints and 100 tracks storage, easy navigation, virtual starting line, heading line, countdown timers and tack assist, estimated arrival time, built-in backlight, dimensions 2.6" x 6.0" x 1.2", display size 1.4" x 2.1", 4 level grey LCD display, display resolution 128 x 160 pixels, battery life +18 hours, water rating IPX7, high-sensitivity receiver, serial, USB, hunt/ fish alender, sun/ moon information, area calculation and track log 10,000 points.