YM Coastal - Radar Knowledge Requirement

[Uricanejack]

Hi all,

Some advice needed - I recently signed up for the Coastal ticket and the school in the Solent tried to push a Radar Course on me, saying it was necessary to pass the exam. This was the first I'd heard of the requirement, and having sailed on quite a few boats, and known a couple of people that had done either the Coastal or Offshore ticket, I was surprised to hear this requirement. Needless to say, I declined the offer, and opted to buy the RYA Intro to Radar Book Pamphlet, and watch a couple of YouTube Videos. I also contacted the RYA direct to check that I wasn't being had by the school. Ultimately they responded saying that the requirement was true (though I didn't necessarily need to do a course), and that this was due to the MCA raising with them five years ago, that they had seen less and less radar expertise amongst candidates, and that it was unlikely, if I couldn't switch on, set up, and use a fitted radar system as a navigational aid, that I would be awarded the YM Coastal ticket.

Thankfully, with a combination of the pamphlet and several Youtube videos, I understand how a radar works, the concept of start up (Brilliance, Contrast, Gain, Range and Tuning), and the views (North up, Course Up, Head Up). But, and we get to the crux of this post, I am a bit confused about the plots. All the examples I've seen reference plotting sheets which are A4 pieces of paper. Is this normal? If you were plotting, would you copy the rough position of a contact on an A4 paper template, or is it more normal to have an acetate template, cut to the size of the radar display screen, with the rings and bearings permanently pre-drawn on it, that you would place against the screen and trace [mark] the contact, and repeat?

Cheers,

NCounties

I presume you now understand the basic fundamentals. You are asking about translating into the practical reality of actually radar plotting.
So if I were plotting.
Truthfully I would rarely use a plotting sheet or board.
I did 99.9 % of my radar plotting. On A reflection plotter. A piece of kit I haven seen in well over 20 years. They have gone the way of the Dodo, the CRT and the hood. For better or worse technology has moved on.
It was an expensive piece of optics, so now replaced by cheep electronics, Electronics apart from being cheep. Have made technology practical and accessible even for my little boat. Which is a good thing.,

I have seen, radars with an electronic plotting ability. Not ARPA just the ability to electronically put an X or an O on the screen at a chosen spot. Which would stay there. The target move on and repeat, providing a plot.
Ive never used one which worked very well in practice. Doesn’t mean good versions don’t exist, I just haven’t used on.
The problem I found was they were to complicated, not for me, for the equipment.
instead of just being a simple X, I could mark spot with. The tried to be clever, or smart and would connect the dots, with an extended line. Which probably was a good idea in the designers office,
it would work ok with a single target, multiple targets and it would join the wrong dots, which I found less than helpful.
So not a system I have seen recently

Could I plot directly on my screen on my radar, with a china pencil, probably, I haven’t tried, or as you suggest putting a clear plastic screen cover and even using a felt tip. May work.
There is potential problem of parrallax, Your mark will only be directly above the target if you stay in the same spot.
How big a problem depends on screen thicknes.

The big problems plotting directly on the screen of my typical basic small boat radar.
It is not stabilized.
This means the target will move ever time the boats heading moves.
And I can’t steer straight.

By using a separate plotting sheet, I partially eliminate this problem . provided I make not of actual heading and relative bearing with each plot.

My radar does show trails. Relative only. Which is kind of like a relative plot.
what I would use in practice. Rather than trying to plot,
Is turn on the trail function. Which can be annoying every thing gives a trail not just the target. So it takes a bit of getting used to.
my options are just on or off.
some have short or long.
others a time interval. Preferably 3 or 6 minutes cause the rithmatics easy.

get a small piece of card, or clear plastic, mark your speed. Or more precisely the distance your vessel would travel for the time of the trail.
eg At 5 knots you will travel 0.5 miles in 6 minutes Or 0.25 miles in 3 minutes,

Now all you have to do is your pre measured speed, on the screen at the end of the trail and you get a good visual of the true motion.

if you are really well prepared, you mark your card with your speed for different ranges.

My simple radar also has a electronic cursor, it’s a useful feature. along with range rings.
in addition to EBL and VRM.

I can use the cursor and rings. to make a rough guesstimate of cpa by turning it until parallel with the trails.

An additional neat technique, Use the curser and rings On a fixed objects trail and I get a good guesstimate of my set,
it’s called a parallel index.

If I were out at night and feel like it. I would use my handy HBC, which I actually keep in my sailing jacket pocket.
to take visual bearings which I can combine with a radar range.
Despite its limitations My HBC is much more accurate than my radars ability to take a bearing.
the radar gives a very good range.
so a combined radar range and visual bearing is actually a pretty good position.

it is also pretty good for plotting.

Take a visual bearing of a ship or other vessel at night combine with a radar range and you can produce a quick fairly accurate plot

Truthfully I tend to just use my mark 1 eyeball and wing it.

Is the above kosher for scrutiny by examiners or the MCA , probably not.
Does it work
Yep.