Any fish finder experts?

[ampersat]

I'm on the cusp of making a decision for a new fish finder for the boat. The particular model I'm looking at is a dual beam (200k/20 degree and 85k/60 degree) at 300w RMS.

A friend told me that 85k won't show fish arches in fresh water. Is that true?

I realize that 200k provides much better resolution. What I can't find is whether I can get a 200k unit that has a wider angle.

While we're on that subject, even my dumpy old Cuda 128 says it will read 60 degree at "high sensitivity" settings. Is this just a matter of not rejecting objects with lower signal returns (because they're on the edges of the sonar cone)?

[Chum Bucket]

I am no expert when it comes to FF so I may not have the answer you're looking for.

I have a Lowrance LCX 18C with the dual 500/200 ducer. 200 khz is only good to about 200 feet. 200 resolution is superior to 50, but this is because the beam angle is narrower. Performance depends on proper ducer install and the FF settings. No one setting fits all. The 200 will read in deeper water, but the 50 khz is much better suited. I don't know of any brands that offer wide angled 200 khz ducers.

Unless conditions prevent me from doing so, I turn off all the noise rejection, fish ID and fish depth and the like. I want to see everything. If you're really in tune with your FF, you can see through some of the fuzz and pick out the fish. My Lowrance does better in the salt than fresh water. Dunno why?

[Starfish]

According to Lowrance my X102c with a 20 degree transducer will actually "see" about a 60 degree cone in the water. The transducer rating is defined by how many decibels of signal strength the pulse has at certain locations, and if the receiver can interpret fainter signals (as can most high-end units) you'll actually get a much wider picture. From experience, my Lowrance does pick up objects farther out the sides than my 3d Humminbird (47 3d) which advertises a 60 degree cone (and which I also like quite a bit).

Before you buy, see if the manufacturer has simulator software or example screen shots on their website. Lowrance has a simulator and I believe Humminbird has screen shots so I presume others do too.

If you're going to be fishing freshwater primarily I'd stick with the single frequency transducer (at least in the Lowrance the single frequency 200kHz transducer has a wider view than the 200/50 transducer on the 200 kHz setting) but if you might use it in the salt the dual frequency sounds like a great idea.

[yeep740]

Just picked up a Lowrance LMS 480DF with has both the 200/50, and is also a gps unit. High ratings but no color. If you want I can tell you where to get it for 500.00

yeep

[fishingls]

If you go with a 60 degree transducer, your diameter of coverage on the bottom is equal to the depth. There are some very good units with 60 degree cones. Also, make sure the screen is full VGA screen (at least 480 by 480 pixels). The extra detail is worth the money. There are lots of good buys on Lowrance units as the new owners of the company are hard at work redoing product lines and models.