Is radar dangerous?

[Baggiolini]

My first trawler, a California 42, had its radar mounted on the forward edge of the fly bridge...don't know what that is called....such that it was aimed at my privates when up there. First thing I had done was move that thing to the mast. Safe or not, if felt uncomfortable.

 

[swampu]

To answer the op's question he should read the defective seaCock thread. To much radar I think.

 

[David Carter]

The owner of the marine electronics shop in Bellingham had this to say when I asked him about the potential effects of radar emissions. The power from a modern recreational-type radar (Furuno, etc.) is so weak that the only way you could cause any negative effect on yourself is to put the radar in transmit and hold your head against the side of the radome for a week. Then..... maybe.... there might be some very slight effect on you.

However, he went on to say, better safe than sorry mount the radar antenna where people won't be in the path of the transmissions. In our case, the radome is well above the heads of anyone on deck or in the cabin. However as a practice we don't let people go up to the flying bridge if the radar is going to be transmitting, or if it's nice and people want to go up there we don't use the radar. We don't operate the boat from the flying bridge so the antenna's position is not a factor in actually operating the boat.

There are a couple of advantages to our lower antenna position so we have not been motivated to move it, plus the installation of both the antenna and the display on its retractable mount in the main cabin overhead are first rate and in the case of the display unit is very user-friendly. However if someone was contemplating adding a radar to a boat that didn't have it I would never recommend a flying-bridge-face location for the antenna.

Flying bridge face mounts were common in the "old days" when masts tended to be solid wood and the cable to the antenna was relatively huge. The flying bridge face was a good place to put the antenna and accommodating the thick, heavy cable was easy. That's why you tend to see these mounts on older boats only.

PS-- With regards to the issue of having a radar on all the time or not, the interpretation of the rule as explained to us by USCG officers a number of years ago is--- Use it if you think you need it. If you have a collision and you were not using your radar you will most likely be found to bear at least some of the responsibility, but the rule does not require you to have it on if you have it. It's totally your judgement call.

That said, we have our radar on all the time we are running. Not because we need it but by having it operating even in great visibility we are constantly seeing what vessels and navaids look like on the screen and can play with the range and bearing indicators if we want to. So we are very used to using it so on those occasions when we might come around a point and run right into patch of heavy, localized fog our transition to "instruments' is seamless and easy.

Awesome pics Marin

 

[David Carter]

Thanks everyone for all your great info. When I was in the navy the last thing I had to worry about was radar. I was a snipe. Boiler technician..when the subs would shoot us with the rubber bullets we had to run over with our wooden cone and piece of rubber and act like we were patching the hole.

 

[Marin]

Awesome pics Marin

Thanks. I took them last fall (I think). It's a fairly common condition here during certain parts of the year although it can happen anytime. An extremely dense fog--- by which I mean can barely see the bow dense--- will form in the channels between the islands. The tops of these bands are not very high as you can see.

As a floatplane pilot I pay them no heed because they are so low but when we started boating in the islands I realized just how tricky they can make things. The fact they tend to form in some of the busier channels--- some mostly recreational boats but some that carry tanker, bulk carrier, ferry and tug and barge traffic, too--- means one can't simply plunge into them with no worries knowing that you'll soon come out the other side.

This is one reason we like to have our radar on at all times. It's easy to monitor being right in front of us and by using it all the time there is no mental transition between running in good visibility and having to transit one of these fog "channels."

Here are a couple more shots taken during the same run. The fog looks so benign, being such a low band, but when you enter it, even if it's fairly bright and even bluish straight up above you, laterally you are as blind as a bat.

A lot of the radarless sportfishing boats run right through it full tilt, I guess trusting to the odds and the fact that the faster they go the less time they'll be in it. But that's not an option in an eight knot boat even if you wanted it. So our radar stays on all the time.

 

[markpierce]

Marin, what beautiful weather you have in the PNW.

A not-unusual summer day on SF Bay:

 

[GFC]

Our radar antenna is mounted a couple of feet above the heads of anyone on the flybridge so I have no concerns about operating the radar while people are up there.

I do like the concept of the broadband radars and their extremely low power transmission. I'm probably going to replace my radar in the next couple of years. I don't know if I'll go with broadband or not. At this time their ability to identify targets at a distance is more limited than a standard radar.

One can make the argument that you needn't worry about targets a long way off, and there's some truth to that.

I do like the ability of broadband radars to discriminate between two or more short range targets. I'm just not sure that feature overshadows the lack of ability to see distant targets.

 

[Peter B]

Two questions all. How much further do you need to see.? Broadband is good for 24nm @ 3G, and 32nm@4G. Also, which object are you likely to hit, one that's near, or one far away...?

 

[CaptTom]

I never understood why someone would mount the radar at crotch level, but I guess if you (1) never use it while on the flybridge, or (2) can restrict it to not transmit in one sector, it starts to make sense. Thanks to those who clarified that for me.

I'm still a little put off when I see radars mounted to angle down. The thought here is that when the boat is on plane (obviously not a trawler) the radar will be level. But I always figured you need radar the most in weather conditions where you wouldn't want to be at planing speeds.

 

[psneeld]

http://www.raymarine.com/manualsearch/

rotates parallel to the water line.
Planing hull boats and some displacement hull boats adopt a higher bow angle when the boat is at cruising speed, so on these boats it may be necessary to shim the rear of the HD Digital Radome Antenna, to compensate for the bow rise and ensure optimum target detection. The amount of shimming should be such that when the bow rises at cruising speed, the radar beam rotation is in the horizontal plane,​

 

[David Carter]

Now I get why the lock guys want it off as we move up or down.

 

[beachbum29]

My first trawler, a California 42, had its radar mounted on the forward edge of the fly bridge...don't know what that is called....such that it was aimed at my privates when up there. First thing I had done was move that thing to the mast. Safe or not, if felt uncomfortable.

We looked at a Mainship and its radar was mounted the same way.

 

[Ben]

. Also, which object are you likely to hit, one that's near, or one far away...?

Peter B - You are my idol

Got to love the common sense argument.

In a fog, I need precision within one mile. I could give a crap about a fuzzy blurb 10 miles away. That's lower on the immediate priority list. I'll bang that a little later than my one mile obstacle.

 

[swampu]

I could give a crap about a fuzzy blurb 10 miles away. That's lower on the immediate priority list. I'll bang that a little later than my one mile obstacle.

You would care about the fuzzy if you were trying to find tuna, not everyone uses the radar to avoid stuff, I use the radar on my fishing boat to find thunderheads in the summer (thus the long range) and birds.

 

[Ben]

You would care about the fuzzy if you were trying to find tuna, not everyone uses the radar to avoid stuff, I use the radar on my fishing boat to find thunderheads in the summer (thus the long range) and birds.

Interesting point. So what range do you have now? I have an older 24NM Sitex. Might get a newer Garmin in time. Any upgrade on my current model would be a plus.

 

[swampu]

I've got the 24mile. I've figured out the thunderheads part real good but the birds I'm working on. We fish here in the North GOM and you can sure make a day better buy running around storms. My present boat doesn't have the range to make the bird part work. My older radar set up was nice, you could scroll the pointer to a "blip" and mark it. When you mark it you could get the lat and long and go to that spot. Great for "finding" wrecks and Private reefs.

 

[Ben]

I've got the 24mile. I've figured out the thunderheads part real good but the birds I'm working on. We fish here in the North GOM and you can sure make a day better buy running around storms. My present boat doesn't have the range to make the bird part work. My older radar set up was nice, you could scroll the pointer to a "blip" and mark it. When you mark it you could get the lat and long and go to that spot. Great for "finding" wrecks and Private reefs.

Mine 24 too, software dated, mid-90s. Not shopping actively, but browsing for next year hopefully.

 

[Phil Fill]

I was interested but at the Seattle boat show all the major bands had no plans for broad band. I was interested as abackup for shorter range and better detail

 

[Ben]

I was interested but at the Seattle boat show all the major bands had no plans for broad band. I was interested as abackup for shorter range and better detail

I like the detail that broadband offers, but also have an affinity to Garmin, and gradually will likely have a Garmin network going. Broadband detail is awfully attractive, but also anything improving my current mid-90s set up is a boost. Software, resolution, and processing power nowadays is pretty impressive.

 

[Marin]

While our Furuno NavNet radar has, IIRC, a 36 mile range, the reason I have to type IIRC before that statement is that we never use it at ranges more then 6 miles. And most of the time it is on 3 or less. In the islands, it is often on 0.5 or even 0.25 miles (it will go down to 0.125 and we've used it at that on a few occasions in the fog).

Range can be important on the ocean or in large open bodies of water like the Strait of Georgia or the Juan de Fuca Strait. But in our waters, not only is the range limited anyway by all the islands but the stuff we're really interested in seeing is generally quite close to us---- crab pot floats, small fishing boats, etc.

Broadband could be a real benefit in this area where these kinds of short ranges are what's important. As we already have the Furuno and it's relatively new we have no reason or inclination to change it. But were we starting from scratch we would definitely check out what the broadband sets had to offer.

 

[Larry M]

Range: When we scan at night we usually only go out to 12 miles and then step down to 3 miles. The Simrad Broadband 4G™ Radar advertised range is 36 miles. Talking to people in the industry, they say functionally to 32-34 miles. That works for us!

Also, there is no magnetron in the HD/broadband radars, so no exposure issues plus instant on and low amp usage.

Our Furuno 1931 is on it's last legs so this is a timely discussion.

 

[Ben]

The Simrad Broadband 4G™ Radar advertised range is 36 miles. Talking to people in the industry, they say functionally to 32-34 miles. That works for us!
.

Is the close-in resolution everything that you hoped/expected it to be? Any screen shots you can share?

Not sure if there's a way to plug through some kind of NMEA 2000 interface and have it show up on my Garmin 740s screen I suppose

 

[Peter B]

Is the close-in resolution everything that you hoped/expected it to be? Any screen shots you can share?

Not sure if there's a way to plug through some kind of NMEA 2000 interface and have it show up on my Garmin 740s screen I suppose

Ben, I think it highly likely that it would be NMEA 2000 compliant, and therefore probably able to link with your current display. However, even if not, can you see a company like Garmin being left behind in the tech race. Mark my words, they will have broadband version out before long.

 

[GFC]

On my last boat I had a Simrad radar/gps setup. I liked having the ability to split the MFD screen to show a short range (1-3 miles) and a long range (24-32 miles) at the same time. The long range was nice when trying to pick up land forms and the short range obviously for avoiding unpleasant encounters.

As to tipping the radar down using a shim when mounting it, as one who cruises a bit faster, I like having the radar beam aligned with the surface of the sea rather than shooting up into the sky neuterizing passing sea gulls.

 

[Larry M]

Is the close-in resolution everything that you hoped/expected it to be? Any screen shots you can share?

Not sure if there's a way to plug through some kind of NMEA 2000 interface and have it show up on my Garmin 740s screen I suppose

Ben: We haven't replaced the Furuno yet but everyone we have talked to and what we have read seems that the Simrad 4G Broadband would be a good fit for us. We don't use the long ranges and if we did 24 or 30 miles would be more than adequate.

The close up resolution is suppose to be one of the strong points.

It is NEMA 2000 compliant but I have no idea if you can interface it with a Garmin system. Simrad is good about emails. If you find out, let us know.

 

[Ben]

Ben: We haven't replaced the Furuno yet but everyone we have talked to and what we have read seems that the Simrad 4G Broadband would be a good fit for us. .

Hi Larry - ok I thought you already had the 4G. I'm in no urgent hurry. I've got a good old Sitex unit now that works. My need is more close-in safety than long range weather or bird flock-detection for fishing. So a year ahead of a potential purchase, the broadband resolution difference is very compelling.

If I take the easy route with my Garmin, I can buy an 18HD radar from them for around a grand and plug straight into the back of my 740s.

But currently my route to broadband is likely buying a NMEA router to plug all components into, at some extra cost.

Again, not there yet, just thinking ahead.

 

[David Carter]

This is a great discussion on radar.. I'd like to see the same on chart plotters.

 

[Ben]

This is a great discussion on radar.. I'd like to see the same on chart plotters.

Ya, I was looking at larger or smaller screens and thought to go with a Garmin 4208 for screen size, but the 740s was slightly more modern.

Plus, I got a deal since the owner was selling his new unit on Craigslist. He bought his, but as he partnered his boat with a friend, and friends girlfriend bought his, he had to sell. So I got a boxed unit with transducer for like 25% off. Made the purchase easy. Works like a charm.

Only down side is touchscreen loves my fingerprints. So if you're a messy eater like I am, think twice about touch screen. (Actually, I made all the prints early, testing and playing, so maybe better in regular use.)

The sonar data and graphics are outstanding. Beats the detail of the GPS part. I just need to finish transducer install.

 

[bobc]

Is the close-in resolution everything that you hoped/expected it to be? Any screen shots you can share?

Not sure if there's a way to plug through some kind of NMEA 2000 interface and have it show up on my Garmin 740s screen I suppose

Here are a couple of 4G screen shots. I don't have a heading compass hooked in, so I can't do overlays. One of the most annoying "features" of the Simrad is that I can't lock the scales of non-overlayed displays. In fact the scale settings usually don't match, as you can see here, one is 0.1 nm, the other is 1/4.

The other interesting thing about resolution. I can often see the wake of boats (including my own). It took me a while to figure out why I was seeing two or three hits on boats 1/2 mile away.

As you can see from the marina plot, the close in range is amazing. If you look, you can even see the walkway down the center of my dock (covered).

 

[Ben]

Bob that's pretty impressive. Thanks for the shots. I can only imagine in the slip there's a lot to bounce off of. Good pic that one. The channel shot is real crisp too.