[Riverman]

My Robalo came with a Furuno B/W radar 2KW dome system
It works ok, I can see other boats but....
I cant figure out how to find birds with it??
What settings to change??
Not even sure if this older unit is powerful enough for birds??
Second, I have the Raymarine C-80 next to it with GPS and Sonar
Would a newer 4KW dome tied to it show bird activity?
The guy at West Marine thought I would have to go up to a 4KW open array to really locate birds at any distance
He said the open array units have a smaller band width which breaks out smaller targets
What do you guys think, or have seen with your radar units??
Thanks

 

[27 sailfish]

Unless the birds are very dense and close - a 2KW radar will have trouble picking them up.You'll see them by eye just as good.

My 4KW dome will pick up birds out about 2 miles - if a good dense flock.

The 6KW color open array is what the pros use to spot birds.

 

[Riverman]

So the guy at West Marine wasnt full of stuff ???
Thanx Skip
I guess my 23 ft CC would look like a chopper with a 6ft blade spinning on the T-Top - HAHA

 

[Grady23]

Open array is the only way to go if your going to use the radar to look for birds. I'm not even sure that the 2k and the 4K domes are interchangable. If you have any DETAILED questions about radar, give Mid-shore electronics in Cambridge a call. They are very friendly and helpful folks.

 

[TerpHeels]

I've got a 4kw 2.0 horz beamwidth 48 mile JRC open array and it finds them to 4 nm just fine. My 2kw dome was worthless for birds but was fine for navigation. He's not lying to u.

 

[tolmaz]

Open Array...I have a Lowrance dome and it couldnt pick up a flock of turkeys

 

[Grady23]

Open array sends out 2 seperate beams and this will give a "wrap around" effect upon return of the signal. The narrower beam and higher power also help with target descrimination. The price is also indicative of the inhanced performance -- It ain't cheap!

 

[ultangler]

The key factor is beam width, (not dome vs. open array; it's just that most domes they make have wider beam widths so many folks mistakenly believe it's a dome vs. array issue) and no one makes any 2kw units I know of that have a narrow enough beam width to spot birds with. 4kw/2.0 beam width will just do the job when tuned right, but remember that in most cases, you're still going to see birds from farther away if you have a good pair (14X or better) of gyro-stabilized binocs.

 

[TerpHeels]

It actually is dome vs array because its the length of the antenna that matters. U've got 4' of antenna (or more) on the array vs 2' (at best) on a dome and most domes r 18". Now build a dome that is 4' in diameter and u'll match the array. IS binocs r the bomb as we use them to "backup" what radar is showing us but there's no way running in the open ocean u're going to beat that swinger on the hardtop for finding them.

 

[ultangler]

I've gotten into this discussion so many times I hesitate to even come back, but...negative, good buddy. Antenna dimension is only one of the factors determining beam width: dimension, wavelength & frequency of transmission, and antenna design. Note JRC's JMA 5110 which has a 72" antenna and a 2.0-degree beam width, versus Furuno's FR8062, which is 48" yet has a 1.8-degree beam width. Again, marketing realities dictate the fact that when you shop for radar you'll notice open arrays have narrower beam widths--not technology or functionality of domes vs. open arrays.

 

[Riverman]

Thanks to all who wrote back, I appreciate the insight
This boat is almost 100% used in the bay, not the ocean so....
I did the math - Raymarine 48" Open Array Radar unit $4500 approx
Full T-Top Enclosure and a pair of stabilizer binocks $3500 approx
Not sure exactly which way I will go but you can probably guess which way I am leaning towards

 

[gooddog]

I am not certain I am following all the concern over beam width when you are looking for targets above the horizon. Seems to me that its the energy and frequency of the pulse that counts and 4K units are naturally superior, pulse length being equal, compared to 2K units. Whatever unit you have, if you can, when looking for birds choose the long pulse length even if you are operating on three mile range and keep in mind that the targets may show only intermittently and that you need to adjust gain very carefully.

The better idea in my mind is to look for boats. Birds may be a good indicator of fish, but so are a few charter guys working above the HS buoy. And even with my little Furuno 1722 I can spot that kind of activity shortly after leaving the creek. If I had a narrow beam on a big radar I could tell you how many boats a lot sooner. But if you stick the ERBL on the mark and compare its data to the range and bearing on the GPS for the buoy you might readily confirm the existence of traffic on the fishing grounds, even in the dark, and head in their direction. Like the birds, these guys fish everyday, and tend to know where to be.

As to binoculars, my Cannon IS are magnificent at identifying something obscure, if I know it is there. But on a small boat, pitching around, they are not nearly as good at actually finding something in the first place as are my old Steiner 7 X 50s that have infinite focus and a much larger field of vision.

 

[Grady23]

I'm not sure if your comparing apple-to-apples when you mention Binocs vs Radar. You can't see very far in fog with the binoculars. You need both on the boat. I don't feel I need a pair of expensive binoculars, but the radar is a different story. I'll go with ya 100% on the enclosure. Being able to stay out of the wind and be dry is well work the $$$.

 

[TerpHeels]

Antenna dimension is only one of the factors

ultangler, w/all due respect, the size of the antenna is a parameter in performance as u yourself stated. So the "negative" is negative in my book. Certainly there's more to performance than sheer size but my generalization stands.

 

[Riverman]

Grady23, I was thinking of upgrading my radar
I already have an older Furuno unit 2KW dome that works for seeing other boats and such
Was looking at options to make it better
I got spoiled watching the color display on the Fin-Finder with Andrew the last trip we did
Able to find a pod of gannetts working 12 miles away was pretty cool