New to fish finders, Help me

[Jake W]

I am new to the whole fish finder world. I recently bought a used 2man boat that came with a trolling motor and a Lowrance Elite 4 fish finder. It is mounted to the trolling motor. I got this to fish in a family pond which at it's deepest is only 5-6ft. deep. I am mainly wondering what area is it showing me? I know it is under but does it read out front and back of the transducer or to the left and right, or all around for that matter? Also, given my depth is there a certain area, for example if I'm at 5 ft does it only give me 20% down so I'm only getting 2ft out to a side? I know this is EXTREMELY beginner info but your help would be appreciated. Thanks and have a blessed day!

[Jig Man]

If it is using a 200 kHz transducer then you typically get a circle which has a diameter of approximately 1/3 of the depth.

[Jake W]

Thanks Jig Man. 

I also wanted to add some more information. The exact model is the Lowrance Elite-4x HDI. It is a 200kHz transducer I believe. In DownScan Operation the frequency options are 455kHz and 800kHz. In the Sonar Operation the frequency options are 200kHz, 83kHz, 83/200kHz, and 200/83kHz. These numbers are according to the operation manual.  

Also, I am not getting the "typical" fish arch (only very seldom). I get it sometimes but mostly not, just blobs for lack of a better word. The question is this: is there a particular frequency setting that would help solve this? Is it a frequency speed issue? Is it because of my lack of depth with it only being at 5ft. deep? Lots of questions I know but I do appreciate the help!

[Jig Man]

It takes movement of the boat to make an arch.  A still boat and a still fish makes a flat line.  The 83 kHz will show a bigger area but I don’t know how much.

[WRB]

What Jig Man posted is accurate; 1/3 dia cone shape means 1" cone diameter at the transducer and 2' diameter at the bottom 6' deep. At 3' deep or the middle of the water column 6' deep the sonar signal area is 1'. Think of a shower head with water coming out of 1" diameter and hitting the floor at 6' with 2' diameter spray of water. This is what the cone sonar area looks like. If the fish is outside the shower spray of water it isn't getting wet or showing up on the sonar displays it moves across the lake. It's like a flash light beam in light in the dark you see what is in the light beam.

Visualize a fish in the dark as the light beam approaches. The light beam is weak on the outer edge and gets brighter in the middle. The weak signal is the thin end of the arc, the middle brighter signal the thick part of the arc and as light beam passes over the signal weakens tapering down. Keep in mind what is displayed is a history of what you passed over. 

Shallow water 2D down sonar isn't much help other then depth readings and locating structure.

Tom

[TnRiver46]

I have two of those model depth finders. You have to be moving to get the fish arch. You probably aren’t going to  clearly “mark” many fish in 5-6 feet of water with any unit (except side imaging), you just about have to bump them with your boat to do so 

[redmexican5081]

83 and 200 kHz are the frequencies your traditional 2D sonar will use.  This type of sonar is the cone shape, 83 will show a larger area but in less detail because more information needs to be represented on the screen.  Typical cone angles are 60^o for 83kHZ and this shows and area of about 1/2 the depth all around the transducer.  In 10' of water you would see a circle 5' in front, 5' to each side, and 5' behind.  When you switch to 200kHz the area shown will be decreased and the image quality better because the cone angle decreases from 60^o to 20^o.  The area would be about 1/6 the depth of the water all around the transducer. Again at 10' of depth you would see ~1.6 feet in front, behind and to the sides.

When you start using DI the same principles apply to the 455 and 800kHz.  455 will show a wider area but 800 will give better detail because it has to show less on the same screen size. The major difference between 2D and DI is 2D shows a cone and DI shows a narrow slice.  There is not much information displayed in front or back of the transducer but there is more coverage to the sides.  2D is a cone shape and DI is more like a triangle. In 10' of water 455kHz will show you about 14' across and 800kHz will show you about 9'. 

[Jake W]

This is all great info. Thank you guys for taking the time to read and respond!