If properly positioned, they help larger, less manoeuvrable vessels detect your presence on their radar screens. They should be located above all superstructures and at least 4 m (13”1’) above the water (if possible). Check to see that radar reflector is securely attached to the vessel and it is mounted in a location that is accessible for 360 degrees
** radar reflectors are not required if:a vessel operates in limited traffic conditions, daylight, and favourable environmental conditions and where compliance is not essential for the safety of the vessel, or the small size of the vessel or its operation away from radar navigation makes compliance impracticable.
** Boats less than 20m in length and boats constructed primarily of non-metallic materials require a radar reflector.