Radar

[Uricanejack]

Very interesting. My experience was with raw radar and plotting with a China graph to get CPA’s of traffic and many lines for blind pilotage into harbours.
The modern radar set ups and AIS are a massive improvement. Radar input into a chart plotter would be a fabulous tool.
Sadly, I only have a RIB and will use in good weather, so won’t be purchasing a radar, but am interested in the developments since I used radar on a ship in the 1990’s.

like as not you already know more than most of those you are asking, You may have forgotten a bit. RADAR hasn't really changed much since WW2. It just got smaller and cheaper. Until. This broad band solid state digital mulit frequency stuff came along.

Most Yacht displays are much smaller than your 24 in and don't have the advantage of a gyro impute to stabilise it. So if you get one its most likely you will have to get used to a small screen unstabilised head up display.
small boat RADARs tend to have small scanners so beam width is wider and bearing definition less. so not as clear as you were used to.
If you used a china graph then you have a good solid understanding of radar plotting and collision avoidance.

You might find a fancy all singing and dancing yacht RADAR, has more features than you are used to. Some more than you will need. None of them have knobs or buttons now just menus'. Which I find irritating. My excuse I'm Over 50. Once you get used to them they are quite easy to use. You can see them in daylight without a hood (best improvement). Practically set themselves up. Auto Tune, Auto Clutter.

MARPA which is Mini ARPA, AIS, Chart Overlay, Can be Stabilised to a flux gate or GPS, North Up and True vectors. Some like mine have none of those.
Mine is about a 6 in screen monochrome green head up only. pretty simple. good for both collision avoidance and navigation. you can even spot bad weather as rain, squalls even increased wind.

RADARS great.
But I don't turn it on very often. Do I need it? No never really have. Do I like having one? Yes JIK.
Would I replace it with a plotter and AIS? No.
Would I add those? Maybe.

 

[Uricanejack]

IIRC it is a legal requirement that if you have radar that it is on while you are underway.

I like to have it on when underway so that I am familiar with the radar picture of regular ports and places I go to.

The radar picture is very different to the plotter picture.

Incorrect.
The legal requirement is to keep a lookout by all available means appropriate to the circumstances and conditions.
Define appropriate.

My definition of appropriate, allows me to leave the RADAR turned of when under sail in good visibility with limited power.

Your second point about familiarity make perfect sense. Your third point is spot on.
If I owned and operated a big huge Princess GP at 15 or 20kn. I would have a RADAR fitted and Operating. Dock to Dock.

 

[Uricanejack]

Just curious, it seems that some people turn the radar on only when they need it, why?

Why the radar is not always on? Is it for saving the electric power, avoid the impact from
micro wave, or what?

I know this is motor boat territory. So like as not we think a wee bit different.

In my case with a small sailboat, usually sailing two primary reasons. saving electric power. and location. My RADAR is at the chart table down bellow. I spend most of my time sailing out in the cockpit or on deck.
In order to use it effectively I need at least one other competent crew to steer while I watch RADAR.

 

[Uricanejack]

I have both digital radar and AIS on board, fitted to a (recent) Raymarine MFD.

Even in the Med where fog is rare, I find it a good idea to have both in operation every time, be it for coastal cruising or longer passages to Italian islands, Portofino or Corsica

During trips from the continent to Corsica, where the boat is under autopilot 90% of the time, having radar is really handy : you can easily track those large tankers/ferries trajectory and speed thanks to the ubiquitous MARPA feature, and take necessary measures in advance (at 20 or 40 nm, a 1 or 2° shift is often enough to avoid those monsters). And the radar "sees" the coast before you can, which is always reassuring.

On short trips, I use radar to track small, fast vessels such as ribs or PWCs that always appear out of nowhere (most don't have AIS).

So all in all, a valuable addition to other nav aids. As for teaching yourself radar operation, I'd say it's really easy with modern tools such as MFDs, map overlay features, artifact cancellation and the such. You'll quickly become comfortable with the image it displays, and will be able to tell a flock of birds from a thunderstorm (or an ominous ferry) in no time.

By the way, as Bandit wrote, it is also my understanding that if you have a working radar on board, you're supposed to use it as a tool to monitor your surroundings and avoid collisions at sea.

I would always recommend a RADAR operator course. But not until after you have some experience without RADAR. Yes you can learn it all from the operating manual and books. Experience certainly helps. But the course is short and not to expensive give good info and hands on practice with approved technics.
Is very easy to become disorientated and screw up using RADAR.

 

[iapetus]

Incorrect.
The legal requirement is to keep a lookout by all available means appropriate to the circumstances and conditions.
Define appropriate.

My definition of appropriate, allows me to leave the RADAR turned of when under sail in good visibility with limited power.

from the COLREGS, Rule 7b:
"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."

Use it (properly) or thou shalt be fined

 

[iapetus]

I would always recommend a RADAR operator course.
...
Is very easy to become disorientated and screw up using RADAR.

I concur. Hence the importance of having it running on every possible occasion, especially on fine days with no visibility or sea state issues, before taking the course.

It's really easy to get lost with all the available options and decide on the best practices (for ex, it's easier to start learning the radar with the Head/Course Up setting, but I finally got used to North Up for both radar and maps)