Radar Interpretation

journey on · Posted: Mon Dec 31, 2012 3:34 pm Post subject:

The only way I've found for learning to use the radar is to use it when you don't need it. Saying that, operating the radar (at least the ones I've used,) isn't easy so keep the manual handy.

Also, let me stress after you've learned to use it by comparing visual scenes with what's on the radar, keep using it for practice. I relearned this in So Cal fog a couple of months ago, when I nearly pronged a boat because I hadn't adjusted the radar for the prevailing conditions: smooth water and going at 12 knts. Luck beats skill, again. So learning and keeping in practice are two complementary skills, practice being more important in the long run.

Also, on the manual's cover, I make my own index of what I think important.

Radar is wonderful, but it's a skill that needs to be learned and maintained.

Boris

colobear · Posted: Mon Dec 31, 2012 3:41 pm Post subject:

Your quote is from, I think, Navigation Rules Part B Steering and Sailing Rules, Section 1-Conduct of Vessels in any Condition of Visibility, Rule 5 Look-out.
If you go a little further to rule 7 Risk of Collision, (b) you see: "Proper use shall be made of radar equipment if fitted and operational, including long range scanning to obtain early warning of risk of collision and radar plotting or equivalent systematic observation of detected objects."

The Colregs 1972 edition which is afik the latest; says:
"5. Look-out
Every vessel must at all times maintain a proper look-out by sight (day shape or lights by eyes or visual aids) and hearing (sound signal or Marine VHF radio) as well as by all available means (My bold) (e.g., Radar, Automatic Radar Plotting Aid (ARPA), Automatic Identification System (AIS), GMDSS...) in order to make a full assessment of the situation and risk of collision."

I'm not interested in getting into a contest here but as far as I know if you have a collision and your vessel is equipped with a working radar; and if you were not "standing a radar watch" you are automatically in violation of rule 5 above and at least partially liable/at fault.

thataway · Posted: Mon Dec 31, 2012 3:50 pm Post subject:

A little pricer at about $140 (you may find it used) is Starpath Radar trainer for the computer. It is highly recommended.

Agree that using it is the best way to learn on clear days.

You should be able to pick up Kayaks with that radar. You will pickup rain squalls and approaching weather fronts.

I recommend tuning the radar manually, not using the auto magic mode. Look at Gain, Sea Clutter rain clutter etc. Learn what ghost images look like--and what is "real".

Never travel faster than you can stop in time to avoid a collision. I don't run that fast in fog, or at night (unless very clear and on other boats around) It just makes traveling at 6 knots safer--not allowing you to trail at 25 knots.

You may need a heading sensor for overlay. I personally prefer it on its own screen.

The AIS is easy, be sure you have the right com port, and baud rate set. Then go to the menu. I have really enjoyed the Garmin AIS thru the Standard Horizon radio. Picks up all of the targets. Some times it seems like too many! But that is all safety. This is also one of the reasons we run two GPS platters. One is only GpS--no sounder, no AIS, no radar etc.

Sunbeam · Posted: Mon Dec 31, 2012 4:36 pm Post subject:

DaveS · Posted: Mon Dec 31, 2012 6:59 pm Post subject:

I've always interpreted the content of the Navigational Rules COMDTINST M16672.2SD the same as colobear.

Aside from how an individual may interpret the rules, I consider the following:
Even when in times of uninhibited visibility from weather, the design of our C-Dorys alone does not provide with a clear 360 degrees visibility without contorting yourself from the helm to look out past the stern when on plane. (Of course, if you have others on board, you can position a stern lookout). Having a radar on and easily seen at the helm, provides a 360 degree watch that gives you a bit of an edge in collision avoidance.

The radar is just one more tool that if it is installed, functional and used may become the one entity that prevents a collision.

It all boils down to using all means possible to increase your situational awareness.

Sunbeam, I can certainly appreciate your observation of a sailboat's inability to keep the batteries charged while under sail. (At least you have a plausible argument if you were questioned).

These are great discussions for us to explore.

Bill K · Posted: Thu Jan 03, 2013 5:59 pm Post subject:

Somebody said that Dusty had made a radar tutorial, here is the link to it.

http://www.c-brats.com/viewforum.php?f=22

Bill Kelleher

Levity · Posted: Thu Jan 03, 2013 7:39 pm Post subject:

Levity runs a Garmin 18HD with a Garmin 4210 plotter/display. I, too, prefer using the split screen mode and learning to interpret in clear weather. It is surprising how many small, fast moving boats have little or at times, no radar reflection. Radar does afford rear vision even when you are facing forward. Radar is great when your eyes aren't.
Mike-Levity