Can't get graph to show archs

[birdswacker]

I have a lowrance x70 and can't get it to show fish archs tried shutting the auto off and turning the sensitivity up but it won't work never had any problems with it before. Any ideas what to do?

[Benny]

If you sitting anckored up you may not see archs.The arch is produced by the boat or fish traveling through thesonar cone.As it enters it is small or low as it gets into the middle of the cone it is at it's largest or highest point and then dissapates as it moves out.

If the fish travels by the edge of the cone no arch will show up, just a flat line or blip.

Turning up sensitivity or gain won't help show an arch, but may help you to see the fish out at the edge of the cone better.

I hope I explained the theory well enough,there are others here that are better at explaining this than I so maybe some one else can chime in too.

Benny

[mnrstrider]

Lowrance's HSOforum is awesome for explain to you how to setup you finder properly, and takes the time to talk aabout fish arches, probably explained the best I've seen. Arches are seen AFAIK only in perfect conditions.