Highly accurate wireless GPS speedometer, compass and bar graph wind shift indicator in a compact, waterproof case.The SpeedPuck is a simple GPS speedometer that was created for sailing but can be used in any sport or situation where you want to see your speed easily. The SpeedPuck has big numbers that are easy to read, it can be installed very quickly and it gives you the accuracy and responsiveness youre looking for.Key FeaturesEasy to read: The SpeedPucks sunlight-readable, high-contrast LCD screen features 1.1" tall (27mm) digits in a font thats optimized for readability. This means that if your boats under 40' long youll be able to mount the SpeedPuck on your mast and read it easily from anywhere in the cockpit, even if you dont have perfect vision.Accuracy you can count on: The award-winning SpeedPuck is completely self contained and can be installed in seconds, without tools. Instead of using a paddle wheel, the SpeedPuck calculates your speed by measuring the Doppler shift in GPS signals to provide you with an updated reading twice a second. The SpeedPuck never needs to be calibrated and maintains uniform accuracy at all speeds. The SpeedPuck uses the same GPS technology as the Velocitek ProStart, which is used by all Americas Cup World Series teams.See what you can't feel: A less than half-knot change in boatspeed doesnt feel like much and thats a problem. The SpeedPuck gives you a new speed measurement every half-second. If you wander into adverse current or your crew on the rail start slacking, the SpeedPuck will tell you right away.Hit the water now: Nobody wants to read a manual. SpeedPuck is a product that anyone can figure out and start using in a few minutes, so you can spend more time on the water.Speed Mode: Displays speed and wind shift indicator updated twice a second. Can be disabled if prohibited by class rules.Heading Mode: Displays heading / course over ground and wind shift indicator, updated twice a second. Wind shift indicator can be disabled if prohibited by class rules.Maximum Speed mode: Displays maximum 10 second average speed, maximum instantaneous speed or flashes between both (user configurable).Automatic shift tracking: The SpeedPucks shift tracker locks