Tip: Position your EBL on any vessel that appears to be headed toward your location. Should that target continue to maintain a course down along that EBL, you'll know that it is headed for a collision with your boat. In navigation, this is known as a CBDR (constant bearing decreasing range) scenario. Change course, speed or both to avoid a collision. If the target veers off your EBL, you will be assured that contact with that vessel will be avoided.