Garmin castable fish finder, how to use

[Gregorym38]

Recently got a garmin castable fish finder, as someone on here recommended, and its awesome. I am still getting the hang of it, and definitely have seen some fish on it. However, sometimes what it shows is confusing, and doesnt exactly look like a fish but is clearly something. I took a bunch of screen shots of the sonar, and I will post a few to give a good representation of what i was seeing. The ones that look like an arch to me is clearly a fish, however i was also seeing a lot of other marks, like somethings the whole screen would be filled with dots, and lines. I dont believe i had my other rod out when i took those pictures, so its just whatever was under the water at my lake. I cant upload some of the photos because it says they are too big, but those are the ones that went through. Also, what is the long icon that looks like a fish kind of??

[Deleted account]

That's a lot of clutter, try turning down the gain until it looks like this...

 

[Gregorym38]

27 minutes ago, Deleted account said:

That's a lot of clutter, try turning down the gain until it looks like this...

 

Ahhh ok so its the gain feature. I was wondering what that was. What is it anyways?

[Deleted account]

33 minutes ago, Gregorym38 said:

Ahhh ok so its the gain feature. I was wondering what that was. What is it anyways?

Like sensitivity.

[Fishlegs]

On 7/2/2022 at 3:10 PM, Deleted account said:

That's a lot of clutter, try turning down the gain until it looks like this...

 

That image looks like clutter from underneath the kid's table after a snack. ?

[WRB]

Gain is power like increasing the volume of your radio. 

I am not familiar with castable sonar units. Your screen shots look good regarding image display.

Keep in mind the depth is shallow 3.8 to 5.4, the transducer coverage angle is like a spot light in the dark only showing what is in the beam of light, the cone angle of sonar.

Generally the cone angle displays 1/3 the water depth, a small area on the bottom getting smaller closer to the TD.

Sonars displays air bubbles or fish airbladder gas, the debris is shallow water looks like snow.

Get a metal picture of the circular sonar cone, 1” diameter at the TD getting wider further away. When a fish moving into the outer edge of the cone area the single is weak. As the fish moves into the center of the cone the signal gets stronger. The arch shape is created from the thin weak signal getting wider in the center and weakening tapering off as it leaves the cone signal area. Longer arches or marks are faster moving fish.

Since your depth is very shallow the sonar area is only about a dinner plate is size, the fish may only be 2”to 6” long or air bubbles from decaying debris.

Also 2D sonar display is a history, not real time imaging. The real time returns are displayed as lines at the far right edge.

Tom