Ducers [Archive] - Fly Fishing Forum

: Ducers

01-24-2007, 03:35 PM
OK I`m ready to lay down some cash for a new FF. After picking out a model I need to decide which transducer to get with it. One says dual freq. for maximum saltwater preformance the other says dual beam for max coverage. I don`t need a ducer that penetrates 1500ft. I want to have as big a cone as I can get to see more bottom in the under 50 ft depths I usually fish. Will I be able to get away with the dual beam which says ideal for freshwater or do I have to get the narrow beam dual freq ducer because I`m putting it in the salt?

01-24-2007, 04:11 PM

Can you give us a bit more information like what make and model for your unit and the ducers you are considering? The dual frequency ducers are usually 50/200 with the 50hz giving you a wider angle cone and less definition with the 200 hz providing the opposite. For our fishing I would probably go with the dual frequency but would want to know more about the dual beam model and what it offers.


01-24-2007, 04:29 PM
I`m sort ofsettled on the Garmin 340C seeing the 250 is no longer available. The thing is I`m usually inshore and I don`t need 1500 ft of penetration, what I want is the bigger cone of the dual beam (45 degrees). I`ve never been happy with only seeing a spot the size of a hula hoop when in 25 ft of water, the dual beam would show a circle 11 ft in diameter at the same depth. But it`s the discription of fresh vs salt that concerns me. Perhaps if the two are the same the discription should differentiate between shallow and deep water. If the dual beam is compatable with saltwater thats the way I would want to go. Sorta like those fancy sideways looking sonars.

01-24-2007, 07:36 PM
Here we go!

"Our new Dual Beam sonar units are optimized to show the greatest bottom definition using a narrow (20) beam yet can still indicate fish found in the wide (45) beam when manually switched. Dual Beam is ideal for a wide range of conditions - from shallow to very deep water in both fresh and salt water. Please note that boat speed, wave action, bottom hardness, water conditions and transducer installation can all affect depth capability. "

I found the one reference above that may clear up the extremely fuzzy Garmin speak about fresh/salt when improperly used to mean deep and not as deep as applied to dual beams and dual freq beams..

Note that in this answer to a FAQ, the Garmin folks say that the dual beam is fresh and salt water capable...

01-24-2007, 09:12 PM
I don't like that it has to be manually switched. With the 200/50 units you can run both simultaneously.

01-25-2007, 07:47 PM
I have never had much luck "seeing" fish on the finder. I use mine for checking out the bottom trends, structure and compsition. So I use the 20hz single. In 20' of water, the cone is like 3' in dia. Not a very big picture, but if I want to see the fish, I could probably just look over the side. I usually fish in water under 30' deep.

If I were jigging to fish suspended off the bottom, a fish finder could be a handy spotting tool. I am usually casting to structure that I can't motor over. Lately I have been turning the finger off if I am fishing in an especially "quiet" or pressured spot. I wonder if the fish can feel the pulses and associate that with a threat. Probably doesn't make any difference.
How do others use their fishfinders?

01-25-2007, 08:09 PM
Check out the www.humminbird.com/productlines_wide.asp?ID=616" Matrix series by Humminbird. I've had great luck with mine. I think it's a 17, but they change the number every year. It's a dual beam 20 + 60 cones. When I fish the Mackerel schools in ~60' of water you can see the school of macks and the Bass in it. Fish in the 60 degree cone show lighter and fish in the 20 cone show solid. You can also set it to return the actual arches and it's got a decent interface with enough filters to get it tweaked out and working without returning many false readings.

Sometimes I use it to find fish but mostly I use it to find structure and basically keep from hitting structure.

Hmmm. seems the units listed on humminbird's site don't really match up to the 17, although that 3d unit looks cool. Here's another link showing the 17 maybe it's discontinued. www.davesmarineelectronics.com/index.asp?PageAction=VIEWPROD&ProdID=5394" I've had great luck with Broken leg Dave Not to be confused with broken leg daves.com

01-25-2007, 10:10 PM

Had to remove the links but Slinger can just cut and paste. Thanks for the info.


I like you tend to fish shallow for the stripes but not always the case with the hardtails. I have had a lot of success marking and following bait to locate them in the rips. Two years ago at Montauk I was in the middle of a great bite but you might not have known it if it wasn't for the big red ball of bait marked on the sounder. Only a few fish were showing on top. Hit the MOB button as I marked the schools of bait and kept returning to hook ups for a few hours until the tide changed and the bait moved. I still have some work to fully maximise the features of my finder and would love to have a glassed in ducer and a digital sounder but for our purposes I think I am better off spending the coin on other gear.