Marine radar was developed over 60 years ago and has become a ubiquitous piece of navigation equipment on all sizes of pleasure craft. While some mariners reserve its use for times of low visibility, many of use our radar systems regularly for two reasons:
Radar provides an accurate representation of above water hazards that can be very helpful in augmenting primary navigation while underway. As long as your radar is properly aligned on your vessel, the radar will provide a very accurate position, range and bearing of all hazards including land and other other vessels.
By using your radar regularly in good visibility, you will become more adept at interpreting the images relative to your observed position. This will provide a much higher level of confidence and competence when relying on your radar in reduced visibility conditions.
Marine radar works by emitting pulses of high frequency electromagnetic fields which, essentially bounce back from structures or objects to the radar antenna to be interpreted and converted into images. There have been many studies conducted to determine the conditions under which these EMF pulses can be harmful to humans. There are varying opinions as to the long-term health effects on humans in close proximity to the source of emission, but it is generally accepted that at close range, when in the path of the pulsed EMF, there can be some potential health hazards.
The exception to this are the newer broadband radars which emit a signal reported to be no more hazardous to humans than the emissions from a cell phone. However, the majority of marine radar systems use pulse technology. The manufacturers warn that you should not stand directly in the path of the radar emission at close range because of the potential health hazards. There is no empirical data to indicate the distance at which there is no danger, but the fact remains that most people are very averse to accepting the risks to their long-term health from close proximity exposure to high frequency electromagnetic pulses.
When a vessel enters a marina or anchorage with a rotating radar antenna, it indicates a lack of courtesy and a lack of concern for the people on the docks or neighbouring boats.
It is considered proper etiquette and common courtesy to turn off your radar before entering a marina or any populated anchorage unless you are truly operating in zero visibility. Similarly, it is appropriate to only activate your radar after leaving a marina or anchorage unless absolutely required for safe navigation.
Observing this etiquette religiously is just one more step to achieving the status of “professional mariner”.