Looking for some radar installation advice

[bsangs]

Once the shrink wrap comes off in mid-to-late March, I'm planning to install a Garmin Fantom 18x dome radar. The plan is to affix it atop my existing transom mounted pole, which is currently topped by a useless domed TV antenna. The pole is roughly six or seven feet higher than my hard top bimini. I also have some other antennae (antennas?) on this pole - AIS, GPS, VHF. The Fantom radar dome will be mounted above these, though not by a significant amount. It'll interface with my Garmin chart plotter. (You can see the pole in the attached photos.)

It's my first foray into radar, so I'm trying to get the actual skinny on this setup.

-- Will there be significant interference among those antennae?
-- And am I making a mistake mounting the radar on the transom pole instead of halfway up the mast? I see plenty of motorboats with radar mounted lower than this will be mounted, so my thinking is it'll work just fine at that height. Am I wrong? (A mast mounting makes this a much more challenging project, but still doable.)

Should mention I'm not interested in detecting bird flocks. This is just for weather, traffic, obstacles, etc. Going to be heading into some foggy waters near Nantucket, Cape Cod and Martha's Vineyard this summer, so bringing a radar into the fold seems like a prudent idea.

Appreciate any and all feedback.

 

[Loren Beach]

Probably a variety of 'right' or 'acceptable' answers to the question.
I favor the stern pole mount for a lot of reasons. Massively easier to mount it and service it later, for one. Another is that the higher the mount the less close up targets will register. And from the point of view of a boat with dangerous close (within a mile or two) targets it works better. For me.
I would note that your present pole is higher than most any others I have seen and higher than one on our boat.
I like to be able to mount and remove the dome from a short step ladder lashed to our stern.
We have the GPS "heading sensor" mounted on a short stalk by ours and the local technician tells me that this will not cause any problem.
Pictured in one photo in this blog entry: https://ericsonyachts.org/ie/ubs/permanent-dockside-fenders.1020/
And here also: https://ericsonyachts.org/ie/ubs/carbon-fiber-radar-pole-project.822/

"Many Happy Returns" as the greeting card saying goes!

 

[Second Star]

The top of your pole looks about 10 feet off the water so that will give your radar about 4 miles "visibility". That is to the water level at the horizon. Another vessel would increase this by how high they are above the water, so in practical terms that would give you 6 miles for a boat like yours or some rocks up to 10 miles for a big tug, ferry, ship or cliff. That is likely the manufacturers "range" of the unit? That would be acceptable to me.
You might get a bit of a shadow forward from the mast. You might miss a buoy or aluminum car topper within a mile or so. If you see this happens, then frequent alterations off base course of say 10 degrees would open the shadow and paint small targets for you. There are lots of boats out there with your proposed mount. If you get a chance talk to one of them about their experience.

 

[Pete the Cat]

I don't see any problem with your height, though I am much in favor of having it on a pole and about 10 ft over the water. I understand that the old sailors' saw about fearing the microwaves from radar (I think the claim was it gave you cataracts) is not scientifically valid ----I get boat and land feedback on mine from 8 or 10 miles out (4K unit), but I never really checked how close to the surface those long distance shots are shooting at the outside of the range and that is the point. My thought is that you want radar low for doing CPA on other boats (don't rely on AIS) and finding and observing buoys in tight passages: IMHO lower is better to gauge separation in feet. In Maine, lower is a necessity to keep separation in the tight passages and crossing separation zones with the fishing traffic--who rely entirely on radar in the soup--if they look out at all.
I have never had any interference with any electronics on my boat with radar or antennas, even when I had a satellite antenna in the old days. Most of the recent GPS plotters and radios with GPS don't even use external antennas any more. Our boatyard skiffs have all the radios and nav gear piled in a center console and antennas clustered all together with the radar dome on the cockpit cover--never had a problem using them and, presumably, the yard guys who installed the stuff do it competently. If you are really going to be picking your way through fog, you might consider getting your radar display on a separate screen or ipad--I have delivered a couple boats with MFD where you either have to toggle, or superimpose, or split screen to see a radar image--and all these options (which are sold as benefits!) have been suboptimal to me in the RW (real world) situation. Just an opinion. Others will differ.

 

[peaman]

I installed a new B&G radome 2 years ago, mounted on a Scanstrut pole attached to my backstay. From your photos, I estimate my dome 2-3 feet higher than yours, and I have been very satisfied with it for close-in and for distance. I went with Scanstrut largely because it allows the dome to pivot as the boat heels, so the dome is always parallel with the water. I doubt you will have issues with interference, but it may be worth combing through the detailed specs of your unit for any guidance on proximities.

 

[p.gazibara]

Cataracts may not be scientifically valid, but you DO NOT want those focused microwaves within a meter of someone’s head. Brain injury can result.

We had strict rules at Navico when testing the radars, they are no joke. The modern pulse compression is much less dangerous than the previous radars, but still worth noting.

Typical radar beam width is about 15 degrees, so as mentioned, if you are heeled and the mount doesn’t gimbal, you will lose some visibility

-p

 

[p.gazibara]

Also, don’t worry too much about height, just get it above your head. Our test boat could pick up and track speed/directions of windsurfers racing in the harbor. We were probably 300 yards from them? Dome was probably 8-10’ off the water. The big radars could pick up birds dive bombing bait balls over 10nm away.
Navico radars are some of the best in the market. Pulse compression was developed there and the hardware team is a really good bunch.

I’m sure garmin radars are very good as well.

 

[bsangs]

Thanks so much everyone. Pole it is.

 

[bsangs]

Another question everyone - how do you have your radar power connected? Through your fuse panels, or directly to the battery? I'm thinking I want a fuse panel connection, because I'd like to actually turn it off when not needed. I'm not going to require it to be on every time I turn on the chart plotter, and standby mode will still suck power from what I've read.

 

[Loren Beach]

Another question everyone - how do you have your radar power connected? Through your fuse panels, or directly to the battery?

For sure-- to a breaker on our main DC panel. The plotter also. And, another breaker for the "instruments" which goes to the KM, DM, and Wind instruments.

 

[bsangs]

For sure-- to a breaker on our main DC panel. The plotter also. And, another breaker for the "instruments" which goes to the KM, DM, and Wind instruments.

That’s what I thought. Odd that directions want me to wire it directly to battery.

 

[Loren Beach]

Odd that directions want me to wire it directly to battery.

My cynical opinion is that the manufacturer is used to selling into a 95% market of small-mid size powerboats where ABYC compliant electrical systems are not the norm. To avoid unfounded complaints of their products not working right out of the box they advise to connect it to the DC source. The small print does caution the buyer to install a proper fuse, but how many boaters really understand how they are compromising the use and safety of their boats by running a rat's nest of wiring to their battery terminals?
Our boats have fully-developed DC systems with circuit protection, so we can do a proper installation.
(My .02 worth....)

 

[peaman]

Another question everyone - how do you have your radar power connected?

My DC panel had one spare breaker which I dedicated to the radome. I ran wiring from another breaker labeled "Instruments" to a new fuse block mounted to the underside of the cockpit deck. That panel has a fuse which powers my Zeus MFD. The "instruments" circuit also powers wind instrument, depth/speed sensor and a couple of B&G Triton displays.

I have full control over what gets power. By energizing the "Instruments" circuit, I will have basic data available: wind, depth, and speed through water. The MFD is setup to not power on until the "On" button is pressed. If the "Radar" breaker is also energized, the MFD will automatically link up with it, but the radar will be in standby until I call for it to transmit via a menu item on the MFD. If the radar breaker is off, the MFD will simply not notice it.

 

[toddster]

Over the last year, I've spent more days than I'd like in zero visibility, sailing by radar and GPS. Don't leave home without them.

I have one breaker for the whole B&G network, joined at a terminal block. 2x zeus, 2x triton, triton edge, Radar, N2K network, ethernet switch. Individual gadgets fused from the terminal block. Only the autopilot has a separate breaker. I bit the bullet and replaced all the rest of my 1990's electronics with new stuff a couple of months ago. The new sensors are all powered from the N2K backbone. Started out to replace a dead speed sensor, but compatibility issues and things just spiraled from there. I'm still feeding aspirins to my wallet. You can control what powers up when by using the yellow signal wires that Navico supplies and software settings. ( I don't recall the Raymarine protocols on this from my other boat.) At least the new stuff draws a lot less power overall. Things aren't happy when they cant talk to the other things, and I don't have a plethora of extra breakers available.

So I've got one boat with radar up high on the mast, and one with it on the stern arch. Pros and cons to both. With the mast mount, the close-in blind spot is bigger, which is an issue when maneuvering in tight spots in the fog or pitch dark. This has arisen a couple of times. The arch mount does create some shading issues for solar panels. And it wasn't compatible with 2nd-generation Starlink antenna. (Starlink would scram and the dish point in some odd direction. Even though it was mounted outside the nominal radar "beam.") 3rd generation antenna seems immune to this so far.

Stern-mount Range: There is a noticeable fade-out of targets, when they pass behind the mast, dead ahead. OTOH, the other night I got a good solid return from an oil tanker 40 miles away. And a group of pangas that were over my eyeball horizon.

Another issue: It pays to have either a separate display for radar or an MFD that allows split screen viewing. Overlay is great, but sometimes entering a harbor, the radar returns obliterate crucial chart data. Probably there is a way to turn down opacity. But you need the radar too. I've encountered unlit piers that aren't on the chart, boats moored with no lights, islands that aren't where the chart says they are...

 

[bsangs]

Another issue: It pays to have either a separate display for radar or an MFD that allows split screen viewing. Overlay is great, but sometimes entering a harbor, the radar returns obliterate crucial chart data. Probably there is a way to turn down opacity. But you need the radar too. I've encountered unlit piers that aren't on the chart, boats moored with no lights, islands that aren't where the chart says they are...

Your last point is one with which we're currently struggling. Our Garmin GPSMap 943sxv has a 9-inch screen, and can be mirrored to our iPad, but the iPad can't be used as a "separate" display. (It'll only show what's on the 943sxv). If we were to split screen the MFD with radar and navigation, I think both might take up too much real estate on one screen, so I was planning to use the overlay. You've given me pause about that though. Think there's a good chance I'll be dropping some boat bucks on another MFD later this season, though I'm going to try the single screen for a bit to see what the experience is like. Thanks.

 

[ConchyDug]

I have a 943sxv at the helm and the split screen feature is awesome. You have almost infinite configurations on screen settings. The tablet mirroring works great for having crew recon ahead while you focus on the route(driver can do this as well but it's about like texting and driving). Having dual MFDs in a small sailboat seems excessive with all the functionality the newer units have. Having the MFD at the helm seems to be more efficient than at the nav table especially when you can mirror to a tablet for route planning below or on the rail or inner tube behind the boat.

I've used the B&G mirroring last year and it's a turd, it was on an 3-4yr old Vulcan9 so maybe they've made some upgrades with their units. The signal lost prompt made me want to frisbee the tablet into the ocean.

 

[southofvictor]

We have an older GPSmap 4208 and I prefer to use split screen. Its nice to be able to cycle ranges separately and I agree that both radar returns and chart objects are easier to see this way.

As we re-wire our panel I’d like to add the option to cut power to the radar separately from other instruments, too.

How much more efficient do folks find the newer MFD‘s relative to older ones? Ours is a hog.

 

[bsangs]

We have an older GPSmap 4208 and I prefer to use split screen. Its nice to be able to cycle ranges separately and I agree that both radar returns and chart objects are easier to see this way.

As we re-wire our panel I’d like to add the option to cut power to the radar separately from other instruments, too.

How much more efficient do folks find the newer MFD‘s relative to older ones? Ours is a hog.

That's the model I replaced with the 943sxv. It seems more energy efficient, though I replaced it late last season, and haven't spent a lot of hours using it. Can't comment on the power consumption with radar return yet though.

 

[peaman]

How much more efficient do folks find the newer MFD‘s relative to older ones? Ours is a hog.

HERE is a post I wrote after upgrading my electronics recently, noting power usages.