How to Navigate With a Boat Radar
You may know what a radar is, but how do you actually go about using one? Remember that radars are devices that measure the time and bearing of surrounded objects. Once these factors are analyzed, the targets or echoes are calculated and then painted on your screen. This gives you a bird’s eye view of a local map. However, you are not just limited to large objects, but also landmasses, weather systems, and numerous other very subtle movements. A simple way of remembering this is that the boat radar shows you what is around you. The rest is left up to you.
So how do you navigate with a boat radar? When you set course for a certain area, very often, you have to struggle against the wind and the current. These factors can shift you off of your course, and if you have no boat radar or GPS system, then you could wind up lost before you know it. In order to determine your position you could use a Variable Range Marker and mark a range and bearing to certain targets. The VRM is a little mark that can be placed over any object on the radar. Once you mark it, the radar will let you know how many nautical miles are in between the object and your craft. You can also take advantage of an echo trail feature, which shows where a target used to be by way of an afterglow. The trail time setting is also adjustable. A boat radar can be used to determine range. Targets within the area reflect the radar pulse and can be traced from the craft to exact nautical miles.
Most boat radars will show a “lollipop” display, which includes vital information like the range of the display, land mass, selected waypoint, boat position, heading of boating, the boat’s bath, fixed range rings and waypoint bearing. It will take time memorizing what various blips on the screen represent. It helps to use your boat radar on clear days so you can teach yourself what an ordinary day looks like compared to a typical boating adventure.
You must plot and track targets manually even if you do have a boat radar. When doing this, you basically take a visual bearing on a certain vessel and then check it a few minutes later to see if its position has changed. Now you are able to plot the target’s position. As far as boat radar positioning goes, the bottom line is that you are taking a defensive, avoidance stance. Try to imagine that any blip on the screen, unless clearly identified, is a threat to you. Keep track of its position until you are sure that it is out of your way.