Navigation lights are used to prevent collisions at night or in times of reduced visibility, and are essential tool in keeping you and your vessel safe. Nav lights allow you to see other nearby vessels, and allow other vessels to see you. They also provide information about the size, activity, and direction of travel. By understanding the characteristics of nav lights, you can determine an appropriate course of action as you approach another vessel. NAVLIGHTS allows you to display a properly colored, properly positioned bow light while underway on the device you have with you - iPhone, iPod touch or iPad! Additionally, if you need an onboard flashlight, tap the button and get illuminated! (if your device has a light) Note: not a Coast Guard approved aid to navigation.