OK...I just got a Garmin 545s GPS Fishfinder without a transducer....so now I need to choose one (Transom Mount). I typically fish in waters less than 200 ft but on rare occaisions I may go deeper. What is the best choice based on your experience(s)? What is the difference between dual beam and dual frequency?

Here is what they offer...

200/50KHz 12/45 degree
200/50KHz 10/40 degree
200KHz 20 Degree
200KHz 45/15 Degree Dual Beam

Many thanks !

The dual frequency ducers are pretty common. Most units will switch automatically so you don't need to figure out, which to use, and when.

So either of those two will work nicely, there is not much difference that you will notice between those.

I have no idea what the dual beam is or how it works.
Also 45 degrees ??? I think that is a real stretch. We would all love to have that much beam---very uncommon.


Good Luck

best way to explain it is

think of shining a flashlight at night in the woods
the beam of light hits trees and say a deer is hiding between
two trees will return a target (or an image)you'll see it
or NOT if it goes completely behind them, out of site...

think of the trees as cover for the moment

likewise in the water
a fish isn't usually stationary and as it moves thru the tranducers
beam it sends you a signal... if it's small and on the edge of the beam it might not even ping
and if its huge then it can shadow or cover
a fish beneath it because the signal can't reach it
but the fishfinder will see it if its " in the cone" angle
of the beam
but if that same fish is just outside of it ( the cone)
it may not see it at all...........

Scuttlebutt,

Are you deadset on getting a transom mounted TD??? I had one for years and when I bought a new bottom machine, I went with an in-hull by Airmar and it was the cat's ass. I could mark while at a 30 kt cruise, no growth, crystal clear picture.

I never was able to mark while underway with the transom mounted TD, I was really happy I went in-hull, give it some thought. Plus, no holes in the transom which could lead to wetness in the future.

Airmar b60 is easy to install and VERY accurate. IMHO better for the boat than a transome mount.

Airmar b60 is easy to install and VERY accurate. IMHO better for the boat than a transome mount.

Keith, I agree. I had the M260 which was way overkill for what I needed it to do, it was a 1KW unit. But man, was I happy with that decision. BTW, I don't work for AIrmar!!!!:kewl: