Thread: a good sonar/fishfinder for locating bottom structure

Originally Posted by chaunc

And thats why i recomennded the fishmark 480. It really is an excellent unit for the money he'll spend. I have the 1197, and 997 hb models now, but that 480 served me well. I also have a 640C fishmark as my backup in case i ever have trouble with my newer units.

I agree with you on the 480. My hunting partner has one on his boat. Nice little unit.

I used to find stuff with my old flasher and catch plenty of fish. I really didn't matter what exactly was down under me, it only mattered that I knew "something" was there.

Originally Posted by VaGunTrader

well, maybe I should reword it.
I don't have a lot of money to be putting into sonar. I didnt have a lot of money to put into a boat either.

I understand.

The primary lake that I fish is loaded with standing and submerged timber, etc. When I identify a pattern, DI allows me to execute that pattern with a greater degree of accuracy. If fish are holding to large stumps, I can find large stumps, if fish are holding in really hairy branchy structure, I can find that. 2D just doesn't give you a precise image, and you could spend a lot of time in trial and error, and not ever identify what the pattern really is.

This is the beauty of DI, and it save me a LOT of time, especially at tournament time, and that's when it really shines. IMO

In 2 boats I have 4 of the 480 and one has gps in it. that one is up front on tm and I can watch fish come up and hit bait or go back down ,which one cannot do with DI, by the way I have di si also and I realise di on side scan is not as good as real di units ,in fact ,probable is me ,but running them both at the same time ,I see more fish on 480 than on si or di. This is not a insults to DI or SI but rather to my igorants of the new units

Genec. The DI on Lowrance HDS is good to go. Dedicated crystal.

I guess it's all in what you want to see. Watching a fish on 2D, just isn't what I need, or what the poster wants. He want's to find structure. 2d will find structure, DI will find structure, and you'll have no doubt of what it is. I see fish on DI, so I'm not sure what you are referring to. Do you see the fish in this image?



Structure and fish

Looks like fish around a bunch of lay down timber..Especially on the SI view.Is that right.?.I know we each will decipher images on our units differently.

From personal experience ranging from $50 used to $170 new:

Humminbird 565, 570, Matrix 35, 717, 718
Lowrance x125, x135
Eagle Fishmark 320, Fishmark 480

I still run a Fishmark and HB 718 on my current boats.

VaGun Trader,
I’ll throw my $0.02 in the hat here and see if I can make this a little easier to understand:

You need to figure out what you want in your sonar unit or figure out what your upper spending limit is:
- How large of a display do you want?
- Black and White (monochrome) display or color?
- Do you want GPS?
- What sonar capabilities do you want: 2D sonar only, 2D sonar + DI sonar, 2D+Di+Si sonar?
- what sort of sonar unit using experience do you have?
Answering these questions will help us all recommend one or more model units for you to consider.


The sonar type you want may be based more on your sonar knowledge and experience than on your wallet – unless you are willing to step outside of your comfort zone and try and learn to interpret new sonar types.

The best sonar type for finding structure is the Si sonar but it is also the most expensive. This will be about half of what you have tied up in the boat just for a smaller 5-inch display Si sonar unit. There is nothing else on the market that can cover as wide of an area of the lake/river bottom as Si sonar can and also show it directionally (left-right of the boat) and in such detail.

The next best for me would be a dedicated DI sonar unit due to both bottom coverage capabilities and the clarity that they can show the structure with. Humminbird DI units also have 2D sonar capabilities as well. DI sonar is probably the easiest to understand what the sonar is showing you under the boat.

2D sonar, due to its wider circular sonar beam, covers the least area under the boat and may not be able to show it to you in a manner that you can understand (based on your sonar use experience). It will show structure but due to the way it displays sonar returns, you may not be able to correctly interpret what sort of shape of structure you have just passed over. I would say that it is the hardest of the three sonar types to learn to use to effectively identify structure. It is, however, the least expensive of the sonar types I have mentioned.