Radar Range

[thaeni]

I just purchased a used Radar (Furuno 1712) and I'm finding it hard to understand where to set the range. The radar has 14 different settings.
from 1/8 to 24nm. How do you determine what setting is best?
Thanks

 

[Don S/V ILLusion]

It depends on how you define "best". The better question is what is it you are trying to discriminate - land 1 mile distant, a buoy 0.25 miles away, nearby objects 100 yards away in fog, a distant rain storm, etc...

 

[Rich Stidger]

Depending upon the height of your radar antenna, the maximum distance to the horizon that will be visible may be only a few miles. My maximum is about 4.5nm. The actual maximum range that is useful will depend upon the height of your antenna and the height of the object that you are trying to see. Just because you have a 24 mile range on your radar doesn't mean that you can see an object (boat, buoy, low land) at 24 miles. You can read up on effective radar range and put in your own antenna height to see your maximum range.

To answer your original question, I can only tell you what I use. When I am in a bay or close to shore I use a range of 3/4 mile. This will allow me to see buoys and other nearby boats. If I am on the coast where buoys and boats are further apart, I use 1.5 or 3 miles for the range. If I am trying to see a thunderstorm cloud and determine where a storm is located, I use my maximum 48 mile range. Note that for a long range like 24 or 48 miles, you will be looking at high objects like thunderhead clouds. You will not see objects at sea level at those ranges.

When I am anchoring, I use the shortest range of 1/8 mile to see other boats around me and help me choose an anchoring spot that is sufficiently distant from other anchored boats.

 

[Bill Roosa]

Which range

It is all about screen resolution. the 1/8 mile range will allow you to display the small area around your boat out to 1/8th mile. The 24 mile range will display a much larger area and the close in or small details will be lost.
My advice would be to sit at the dock and play with it for a while on all the ranges to see what works near the dock best then go to open water 2-3 miles from a shore and play with is again. Then go somewhere that gives you a 24+ mile target over open water and, again, play with the unit.
Radar is a lot like riding a bicycle, you see someone else do it and it looks easy, when you try it does not even seem possible to just go straight at first, then after a while you are wondering what the big deal was when you started.

 

[Don12364]

First users of radars have long apprenticeships.
I recommend using it as often as you can in good clear weather. At first you will not be able to associate targets on screen with those in the real world around you. It will take quite a few hours to learn the knack of identifying other boats and buoys on both screen and water. Remember you will need to do this without fail if you find yourself in fog; so practice all you can.
Switch ranges and change the gain settings until you are thoroughly familiar and know what to do instantly to set up the display and make sense of it.
Remember the cardinal rule. If it is on a constant bearing and the range is reducing then it is on a collision course.
Learn to make radar plots and how to use the Variable Range Ring and the Electronic Bearing line to take a fix and also, if you have radar on board you will be legally expected to know how to use it should a collision occur because the COLREGS require this.
Radar is a wonderful thing but interpreting the display is not at all intuitive - until one gets used to it - then its fun.