Reading the fish finder

[AwesomZZ]

So, I've recently bought a Humminbird 345ci, the portable version. I've gone through the manuals and stuff but I still dont understand how to read this thing. For example, fishes are suppose to show up as arches, but of the 3 times I've been out with it on my boat, not a single arch. That is not possible. Can anybody give me any tips on how to setup this thing and read it? Right now, it doesn't seem to do any better than my very basic 10 year old eagle fish finder which just shows everything as a big blob.

[Craigums]

if everything is a blob you may have your sensitivity set to high?

Are you getting a good reading on your bottom? Does soft bottom areas show up as yellow and hard bottom areas red?

[AwesomZZ]

I meant to say the old one shows everything as a blob. Yeah, I'm getting the hard bottoms and soft bottoms. On the 345, its much more clear and I've adjusted the sensitivity. Its hard for me to tell what is what though. How do i know if what looks like weed is actually a underwater tree? Or that blob of green, is actually a fish? What do the other colors mean?

[solbes]

Well the blob of green is actually a 13-18" male walleye, but when it turns yellow you got yourself a 13" rock bass. Bullheads are blue of course. I kid, I kid.

I've had an HDS 7 for 3 seasons now and I'm still learning how to interpret the image. I consider the installation to be optimal and I get fish arches if they are fully in the sonar cone. But interpreting whats on the bottom can still be a mystery. On slow fishing days I like to drop the underwater camera down to compare the sonar return with an answer of what it really is. I've gotten much better at finding fish buried in weeds, vs seeing just weeds. You even start to get a feel for weed type. Rocks, logs, sand, mud; these can all be differentiated if you can verify with a camera image.

Back to getting arches, I wouldn't be surprised if your transducer is off level (front or back) from bottom. If you are getting a partial arc, you can diagnose whether its pointing slightly forward or slighly rearward. Remember, it doesn't matter how it sits on the trailer, it's how the boat sits in the water vs bottom. Is it level side to side? Is it low enough on the transom to get a smooth stream of water?

Also do you have noise rejection turned high, low, or off?

[dairyman]

good point on being level---------I made sure my boat was level on the trailer first and then leveled my transducer from there

[ClownColor]

If you can switch frequencies, the lowest one will show the best fish arches if traveling slow.

youtube Alton Jones understanding your sonar