Pinwheel Lines on a Radar Display

Pinwheels appearing on a radar display can be caused by cross-talk. Cross-talk occurs when two or more radar devices are operating within the same proximity. Cross-talk will produce a spoke wheel effect and sometimes display ghost images on the screen. 

The spoke wheel effect may appear as dotted lines curving outward from the center of the display. This will typically occur when the two vessels operating with radar are located some distance apart from each other. When two or more vessels are in close range of each other, cross-talk can cause display ghost images to appear on the screen. These images will appear and then disappear randomly.

Turning on "Cross-talk Rejection" will help eliminate or lessen this interference. 

Refer to the owner's manual of the chartplotter for instructions on using the Cross-talk Rejection.