Quote Originally Posted by arca54 View Post
I am posting this here too any thoughts from you guys

I have an eagle 320 on trolling motor and a480 on the console
My question is do any of you get the images of fish arches like they show in the ads?I go out and adjust mine every way i can and have never read anything like that,I can find brush and other cover but can never really say i see anything as fish for sure.Am i adjusting something wrong if i turn sensitivity up i get dots and lines but no arches.Thanks for any ideas
(pic is from ad)
If you have the fish symbols turned off, and the sensitivity set up a little ... those dots & lines are now the "fish" symbols. Arches only come when a fish enters, then leaves the cone. Something has to be moving :p ... either the boat or the fish. You're also going to see "trash" markings, that aren't anything you need be concerned about, especially if the sensitivity is set very high. Chart/scroll speed can change the markings, too. Even if the fish symbols are on, not every one of them is really a fish.

I usually just turn the unit on, set for automatic, and just use it to stay in a certain depth range ... or find a brushpile/cover that's submerged. About the only time I pay all that much attention to fish symbols, is when the large fish symbols are stacked 3 or more deep :D ... which is usually an indication of a school of fish, of decent size. Then again, I'm only fishing straight down under the boat on rare occasions. Mostly I'm casting away from the boat, so I'm more interested in what depth of water I'm sitting over ... so I can gauge how deep the cover I'm casting to should be (if I don't already know).

Have you read/watched the tutorials/emulators on depth finders ?? Here's what most of them have to say about "arches" -

"To display "arches", the fishfinder relies on the characteristics of sonar. When a fish passes directly through the transducer's beam, it can form an arch on the display screen. The size of the fish arch is affected by the sensitivity setting of the unit, your boat speed, the depth of the water and the location of the fish within the sonar beam. Often only partial arches will be displayed because the fish does not travel directly through the center of the beam."

... cp