Need help with depth finder

[Southeasttackle]

I have never really used a depth-fish finder before. Until now I have only used one to find the depth of the water. I am using an Eagle cuda 168.
My question-s are = how can you tell if the so called fish on the screen are really that and where might the fish be in relation to the boat. The transducer is located on the right rear of the boat.
Any help is greatly appreciated.

[crappieken]

Southeasttackle - Here is a good article on depthfinders.
http://www.fishfinder-store.com/howfifiwo.html

[TapOut64]

I have an Eagle cuda 168ex which I bought mainly for the water temp feature. (probably what the ex means) I havn't been happy with this unit running in auto mode as it give back a lot of false signals, and I mean a lot. I have to put it in manual and turn the sensitivity down for it to be accurate.

Any fish you see on your fishfinder are generally below your transducer. The cuda 128 has a 20 degree cone angle with up to 60 degrees in high sensitivity.

In 30 feet of water, a bottom finding unit that emits a 20-degree cone angle gives you a search radius of approximately 10 feet. So that would mean at 10 feet you're probably only looking at around 3 feet across.