Features Garmin SailAssist for GPS 73 includes virtual starting line, heading line, countdown timers and tack assist Waterproof (IPX7) and it floats! Marks your favourite locations to easily navigate back to them High-sensitivity GPS marks and stores 1,000 waypoints and 100 tracks Display WxH: 3.6 x 5.4 cm / 128 x 160 pixels / 4 level gray LCD Serial and USB Interface Size WxHxD: 6.6 x 15.2 x 3.0 cm / Weight: 203.1g with batteries Uses 2 x AA batteries (not included) / 18+ hours battery life Quickly Acquires Satellites High-sensitivity GPS receiver quickly locks onto GPS signals and tracks your location even in challenging locations, even below deck in most boats. Mark Important Waypoints Whether it’s a hot fishing spot or a racing buoy, you can mark and store 1,000 waypoints and 100 tracks to navigate to and from time and time again. SailAssist SailAssist helps you sail more effectively with heading line and tack assist. Tack assist lets you know when to tack based on whether your boat is getting headed or lifted compared to the boat’s optimal tacking angle. For those who like to race, there’s virtual starting line and countdown timer to make sure you cross the starting line at the right time. Store Important Data GPS 73 is NMEA 0183 compatible. To transfer data to your device, it easily connects to your computer via USB. If you’re into racing, crusing or fishing, you can use the built-in celestial data, which includes sunrise/sunset times and a hunting and fishing calendar, estimated time of arrival, other calculations and marine data. High-contrast Display GPS 73 has an intuitive user interface with dedicated back-lit buttons for quick and easy operation. Its high-contrast display makes it easy to read in all lighting conditions.