Radar Interpretation

kennharriet · Posted: Sun Dec 30, 2012 7:27 pm Post subject: Radar Interpretation

I installed the Garmin HD18 Radar and have it piped into a Garmin 640s Chartplotter. I have not yet had it on the water and have not used radar before. Are there any good resources for learning how to interpret the radar signal or is it intuitive? I also have a new VHF radio with AIS connected to the chartplotter. I have not had a chance to play with overlaying the AIS targets and radar on the screen options. Any tips?

rogerbum · Posted: Sun Dec 30, 2012 7:35 pm Post subject: Re: Radar Interpretation

kennharriet · Posted: Sun Dec 30, 2012 7:53 pm Post subject:

Thanks Roger. I meant to say Garmin 740s. Will this type of radar also see fog or only solid objects? With the proper adjustment, will it detect a couple kayaks in the fog at say 200 yds? Will it detect a small non metallic craft without a radar reflector? I realize it is just another tool and no substitute for see and avoid.

Sunbeam · Posted: Sun Dec 30, 2012 8:02 pm Post subject:

rogerbum · Posted: Sun Dec 30, 2012 8:08 pm Post subject:

colobear · Posted: Sun Dec 30, 2012 10:50 pm Post subject:

I would recommend a book, "The Radar Book" by Kevin Monahan, Fine Edge publishing. It takes radar from very basic principles to lots of specifics for using radar for collision avoidance and navigation.

Sunbeam · Posted: Sun Dec 30, 2012 11:06 pm Post subject:

I just looked that book up - thanks for recommending it.

Sunbeam

hardee · Posted: Mon Dec 31, 2012 12:57 am Post subject:

kennharriet,

You will find, if you follow the advice from above, that using your radar all the time, you will rapidly learn what a kayak looks like and an aluminum skiff and what the shorelines look like. You will see rain, and even birds, depending on the settings, gain, and distance are the ones I use most, and it will become your friend.

I usually like my radar clean and straight so don't often run it in overlay mode. I like the black screen with the yellow blobs. Easier to pick out what's there and not. The AIS info goes to the chart plotter and the radar is kept on it's own screen. (Actually I use a split screen set up on my display) but it is run as two separate screens. I love the AIS functions and find I use it more frequently than I thought I would. The radar is always on, ( a little matter of Colregs and collision avoidance discussed at length in some other threads.)

You will not be sorry for making those additions.

Harvey
SleepyC Moon

starcrafttom · Posted: Mon Dec 31, 2012 2:08 am Post subject:

I agree that using your radar is the fastest way to learn it. I have made a habit of always having it on and you would not believe how useful it is on the sunny days. Play with the settings and learn how to quickly adjust it for objects close and far. I have used mine to set how far a way fog it but a better use is to see whats in the fog.

Overlay is the best way, I think, to use the radar. Saves on screen space and you can see if the blob you see on screen is a channel marker or something else on the chart. I have used mine to spot kayaks, small boats and even large snags. One of the best investments on the boat.

Walldog · Posted: Mon Dec 31, 2012 7:32 am Post subject:

I have a Garmin 18D also. I usually run with it on as other posters recommended. Yesterday was a great day to use it crossing our bay. There was the Pirate Ship, a couple of head boats ($20 head for fishing), an Eco Tour boat, a boat pulling a parachute. and several fishing boats. All going different directions in a limited space. Non with AIS. I acquire the targets, so I can see direction and speed of travel using the Overlay screen which I have primary with a small Nav screen and engine monitor screen filling up my 5212 display. I know I could have threaded my way through without the radar, but the practice sharpens my skills for when visibility drops to nil. And it does add a measure of safety in good visibility. If I had a smaller screen, my choice would be the radar overlay as a primary display. Congratulations on your new radar. As you learn to use it, you will find it to be an invaluable tool.

Gene Morris · Posted: Mon Dec 31, 2012 10:58 am Post subject:

Sunbeam;

I also have the HD18 hooked to a Garmin 3210. My old radar was the Garmin 41. The new 18hd is fantastic and much more sensitive than the older one. Our bay has some shallow channels marked with PVC pipes The new radar will pick up each pipe seperately and will also pick up flying/diving birds when salmon or tuna fishing. Like said above it is best to work with your radar in good visibiliity you will see that the radar doesn't lie to you and you will get used to the targets and what they mean.

Gene

matt_unique · Posted: Mon Dec 31, 2012 11:49 am Post subject: RADAR

I find many aspects intuitive when you turn it on, but learning the nuances of your system takes time. You should always have it on during the day and in good weather to learn those nuances. Plus, when is it bad to have a pair of electronic eyes during the day? In busy ports I love it.

One of the things you will learn and perhaps be surprised with is how small a signal some vessels provide. I do not regret my trilens radar reflector for a minute and have tested it in pea soup fog.

One thing that is very important is to adjust your newly installed radar such that items dead ahead show up on your screen as dead ahead. You will most likely need to adjust this a few degrees. Test this carefully on a calm day with a stationary object offering a big return.

What a great safety tool to have aboard. My longest cruise 'under the hood' in thick fog was 30 nm. It was a beautiful thing to see through the fog and enjoy the flat calm seas with no wind.

kennharriet · Posted: Mon Dec 31, 2012 11:54 am Post subject:

Thanks all for the education. I really appreciate the benefit of your collective wisdom and experience.

The catalyst for getting radar was from an event last spring. We were at Princess Louisa on our first major boat adventure and got word of a family emergency. We needed to get back to the truck in Bellingham and travel to CA asap. We encountered fog on the return trip which delayed our egress. I was tempted to push the fog because of the urgency of the situation. We also had a minor mechanical problem with a stuck thermostat. This kept us in Friday Harbor overnight and prevented me from pushing the fog until it lifted.

Even with the new tools we do not intend to get into situations where it is essential, but it will be nice to reduce risk if we have to in the future. I look forward to learning more about radar use. Where else can one find a hobby where your spouse asks you to buy another toy (I mean tool). "OK dear, if you really think it's necessary".

Thank, Ken

SENSEI · Posted: Mon Dec 31, 2012 12:11 pm Post subject:

If memory serves me right, I remember a good tutorial was posted here quite a while ago by Dusty about radar usage. I have looked for it to no avail. maybe someone can find it for us.

colobear · Posted: Mon Dec 31, 2012 1:12 pm Post subject:

Ken,
Your post aptly illustrates Dreamer's wise maxim "The most dangerous thing on a cruising boat is a schedule". You made a good choice to wait and arrive. Having soapboxed, radar is an indispensable tool for us. We have it on all the time except when we are in a marina or next to another vessel. Many time I have picked up a vessel on radar and then looked around to find it just out of my normal vision arc. It is particularly useful for seeing vessels approaching from behind and...official rules in the collision regs. require you, if you have radar, to have the it on when underway. I have avoided being hit in a t-bone collision in fog when my radar warned of an idiot going 20+ Kts in dense fog. I made a sharp turn and he roared through never even knew we were there! I prefer to use it in overlay mode and it really helps me steer a straight course in fog.