Garmin GPS 73 SAILASSIST - Includes several sailing features such as virtual starting line, countdown timers, speed history and tack assist LONG BATTERY LIFE - The handheld can operate for 18+ hours on 2 AA batteries MARINE FEATURES - Offers marine features such as MOB, marine alarms (off course, anchor drag, etc.), route planning and navigation EASY TO USE - Intuitive user interface with dedicated backlit buttons for quick and easy operation USER DATA STORAGE - Stores up to 1,000 waypoints and 100 tracks that help you get back to your favorite spots