Radar - Dome vs Open Array

[Vincentc]

I trust the open array provides better performance, but I wonder how much. Is it worth the added cost and space?

I have Garmin 4212 and 4012 plotters on a 43 DCFB and would like to add radar. I assume I can just plug in.

It is tempting to just follow the GPS plotter, in bad visibility, and have to remind myself that while it shows where buoys and islands are supposed to be, it does nothing for other boats or uncharted obstructions.

In limited visibilty I am not going to run over 8 kts unless trying to get out of someone's way. While I try to avoid it we do get caught in fog and rainstorms on occasion and do run at night.

I would appreciate the benefit of your comments / advice / experience before I start radar shopping. Not only regarding the question of dome vs open array, but also compatibility with the Garmin system and performance between manufacturers.

Is Garmin the only / best choice for a radar add on in my case or are there other options I should explore?

Thanks for you assistance.
Vincent
43 DC Lilly Marie

[Genesis]

You can only use same-brand designed to work with your existing, unless you want a separate display. If you do, then it matters not but it won't interface.

The dome has materially less SEPARATION of targets. That is, two targets close enough together will appear as one. That is the primary difference. The open has more power (usually) but you're limited by the line-of-sight for targets at ground level (e.g. a boat, marker, etc) anyway.

IF you're interested in using it to spot working birds (fishing) then you need the open (discrimination) AND power.

[Walter P]

Ditto on Genesis' comments.. Additional information is that not only is open array better for seperation, the larger the array the better the seperation. Along with open array, you should be aware that the popular 4KW sets are more than adequite for normal nighttime cruising, be advised that if you intend to be in areas of frequent heavy duty fog or rain, the higher the power the better you will "see" through it. There are of course cost factors in mind, but that's your call as I won't put my hand in someone elses wallet.

Walt
'82 48' Series I MY
Long Branch, NJ

[JLR]

FWIW, I have both a 4KW dome unit and a 6KW open array on my 56 MY. I added the 4KW dome on the brow so that when I remove my radar arch for trips up to Lake Champlain, I have radar. Under normal conditions, I always operate both at the same time. Hence, I can look at both displays simultaneously. To tell you the truth, the difference is marginal at best between the two other than separation. I also have the 6KW unit on my 43 open. It is plenty of power and please also recall that the curvature of the earth is the primary limiting factor in its use for distance. So, if money is the issue, the radome should do the trick. However, it is a Hatteras and the open array is, how shall I say this, more "manly". Just my thoughts.

[REBrueckner]

I agree with the prior posts.

It's the height of your antenna and the size of the target that usualy limits range rather than the power of the antenna array. These 45 foot sportfish boats with six foot long open array antennas at 15 foot height (just for illustration) are ridiculous...but as noted look pretty cool.

A 24" antenna should serve you well, nothing wrong with larger if you don't mind spending more. On my 48 YF, I had a 1989 Raytheon dome antenna on the roof, and added an arch maybe seven feet higher with a 1999 24" open array Furuno...I'd give the slight edge to the Furuno, but maybe that's because it has more intuitive easier to use controls....on rare occasions at anchor when I have compared the two simultaneously, maybe the Furuno would have ever so slightly better detail; underway I 'd never notice it because I'd be navigating via other tools as well...no time to stare and stare.

I opted for black and what rather than color. I am happy with B & W for all my instruments but the color also passes the "looks very cool" test. I don't know what the current price differential is. Others can comment whether it really helps them do a better navigation job.

[sgharford]

I installed full blown Garmin electronic package on my 43DCFB over summer that includes 2x 4212’s and Garmin GMR 21 radar (2 kW 24” dome). Was going to install GMR 24 (4 kW 24” Dome) but was told because of mounting height I wasn’t going to see any big improvement over 2 kW as far as range goes, so I saved some money and power drain and with 2 kW. I love Arrays but couldn’t justify the extra $4k as my intention for use sounds similar to yours (these are not Convertibles).

Piece of advice I can offer – this was Not listed on Garmin Web-site and it took 3 separate occasions with calls to Garmin Phone techs before one figured this out – You may have to update firmware on your 4212 and/or 4010 for it to recognize radar. I purchased everything new over past summer and depth finder as well as satellite radio worked fine, but couldn’t get 4212 to recognize radar. As everything new install I drove myself crazy thinking it was wires. You can get latest firmware updates on Garmin site – for 4212 you need to put download onto SD memory card (camera type) and follow boot instructions (also online).

Also, since you are thinking of doing this, the power and network wires that come with Garmin radars are in a single sheath with warnings not to cut wires. However, if you need to run them thru aluminum tube radar arch you may have to cut. It is OK to cut them down (nothing to do with impendence or resistance), you just have to be aware that one end of network cable (standard RJ45) is type “A” connection, the other is type “B” connection – making this a crossover cable by computer network standards. The Garmin phone tech told me so many people screw this up that they decided to put label on cable warning not to cut.

[JLR]

Just to chime in again, I do not recommend 2Kw units and would stick with 4Kw or up. I have had poor experiences with the former. Also, I just replaced an older color radar with a newer B&W radar. I am old school and to me, the color radar made absolutely no difference whatsoever. In fact, I tuned it to as close to a black and white return (actually green) field as I could get. I would not spend money on color.

[Trojan]

I have all Furuno on the bridge with a color 24" dome. I have no problems with separation. At the lower station I have a black and white (green) 36" Raytheon dome and the Furuno display plus a Garmin GPS.The domes are stacked one on top the other. I like the Furuno better. Size per size there is NO difference in antennas. They work the same and do the same. It would be a trip to mount a 6ft. or 8ft. dome on your bridge. . The gear box is large and tall on the open array. Hay it looks cool up there just turning around. Radar in a dome, holey-cow, people might think its a TV antenna. There goes your ego. In close, size doesn't really matter. With more power the larger the antenna is required to see distance. Bare in mind that radar has a hard time seeing any fiberglass boats. It's the metal objects that show up the best. Floating trees, fishing nets and cork floats seldom show up. At night, I run 3 displays, radar, GPS and depth. And depending on conditions a spotlight. All the electronics are linked together through a hub. Including the lower station. In the lower station it will display all three, but only 2 at a time. The b/w Raytheon is harder to separate and distinguish objects. I would never have anything but a color radar.

Bill

[Vincentc]

Thanks for the excellent comments. You all have addressed my concerns, and then some. ( How did JLR know about my uh-identity concerns?)

I agree, the open array is much more cool and ship like. However I'd rather save the cost spread if the performance difference is not significant, as it relates to my needs

The only feeding birds that have concerned us are the sea gulls that gather when appetizers blow off the aft deck. It does not appear that the ability to discern between two objects close together is that important, since I want to avoid hitting both of them.

Vincent

[JLR]

VincentC- careful about those close objects. Often times, it may be jetties on either side of an inlet or head buoys marking the entrance to the inlet. Needless to say, you need to split those two objects.