Testing?? Fish Finder

Does anyone know if there is a way to test a fish finder to see if it's working properly. So far all I could come up with getting my buddy to go out with his boat and compare. I just never see the fish arches on the screen like it shows in all the pics, or are they looking at whales . This is the 1st one i ever owned and its been on 2 different boats so I don't know if it has ever worked like it's supposed to. Also if I mount it thru-hull on a hockey puck will that eliminate the interference I get from my main motor? I can see anything but bubbles when I run my 60hp. Even at idle I get funky depth readings. Tells me it's 160ft when I know it's only 20ft. Seems to be ok when I run the kicker which is on the other side of the transom though.

Re: Testing?? Fish Finder

You apparently have the transducer mounted too close to the motor and it is the aerated water that is causing the problem. You will not see arches unless there are actually some fish in the area. Sensitivity not turned up high enough. If the unit is providing accurate depth information then the unit is working. Some locators are simply better than others.

Re: Testing?? Fish Finder

What Depth/fish finder do you have, there are thousands of them.

Depending on what depth finder there should be a setting you can turn on/off fish id.

You can probably get a manual for it off the manufatures web site.

As for through hull sending units, they usualy dont work well unless they are designed for it.
The puck type are usualy used on trolling motors.

As for getting inacurate readings underway, I get that sometimes and ive got mine mounted to the transome.