Here’s some great advice from Skipper Tipsabout how to use RACONs to help you navigate safely when you’re cruising along the coast:
Imagine you are approaching the busy port of Miami on a pitch black night, in blustery winds and a choppy sea. When still 6 miles away, you turn on your radar and see a cluster of buoys, beacons, and vessels, and each target appears as a separate dot on the radar scope.
Your eyes strain with fatigue as you scan the cluster of contacts, trying to pick out the Miami sea buoy, marking the entrance to the harbor. What twenty-first century innovation can make finding this buoy super simple?
The chart (illustration above) shows lighted buoy “M” is painted with red and white vertical stripes, which means it is a safe water buoy (deep on all sides). The abbreviation Mo (A) shows this buoy carries a white light, flashing the Morse code letter A (short-long flash).
A large circle surrounds the buoy, which means electronic devices are installed. This buoy is equipped with AIS and it also has a RACON, which stands for radio transponder beacon. Note the two dashes enclosed in parentheses to the right of the abbreviation. This is the Morse letter ‘M’.
As you get closer, you will see two long lines painted on the radar screen to make it much easier to pick out the sea buoy.
RACON signals are staggered to conserve energy. US RACONs have an intentional off-time period of about 20 seconds (on for 20 seconds; off for 20 seconds). Other countries may use longer intervals of off-time compared to on-time, such as on for 20 seconds and off for 40 seconds.
The distance at which your radar antenna will ‘see’ a RACON signal is limited to the height of your antenna and radar signal transmission power, and may be affected by heeling or rough weather. RACON signals are powerful enough to be picked up at distances of up to about 17 nautical miles off the coast.
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