Thread: If it ain't broke, don't fix it

One last question, May have been answered. I see fish on both sides of the si image. This tells me the the school was directly under the boat.
If if was just on one side, it would show only on that side? Or am I nuts.
It could have been a school so big as to be under the boat AND around the poles?

I could be wrong, but I think the fish are under the boat, kind of of hanging off the edge of were the water is getting deeper and the dock is just to the left.some of the fish are probably around under the dock, but most are not

Originally Posted by brettw

One last question, May have been answered. I see fish on both sides of the si image. This tells me the the school was directly under the boat.
If if was just on one side, it would show only on that side? Or am I nuts.
It could have been a school so big as to be under the boat AND around the poles?

Originally Posted by kosmo

I could be wrong, but I think the fish are under the boat, kind of of hanging off the edge of were the water is getting deeper and the dock is just to the left.some of the fish are probably around under the dock, but most are not

I think both of these are good suggestions of the fish school ...

Rickie

Originally Posted by rnvinc

The dock posts are approx. 18ft from the xducer ... Therefore painting the structure as starting approx. 18ft to left of the center line ...

As the left SI sound pulse is traveling toward the dock posts ... The first 18ft of its travel is merely thru water with no reflected echo ...therefore black (no data) between the centerline and the Left SI 18ft Range line ...

It's not until the sound pulse has traveled 18ft from the xducer that the sound pulse 1st contacts the dock posts ... Then starts painting the dock post reflection ...

The fish school is more rounded ...

Some of the individual fish (of the rounded school) are closer to the xducer than the dock posts are ...

The individual fish (of the rounded school) that are closest to the xducer would be painted closer to the centerline ...

I agree ... Vertical posts are difficult to discern in an SI image ...

Rickie

Yeah, I get the distance not depth translation of the ping (I have a DI unit). That's exactly why I don't understand why there is no dock pole image above the fish. Even a ghost image appearing would make more sense than no return signal image at all.

All I'm saying is ... say the transducer is about 1ft under the water, and it's supposed to be shooting out a sonar ping at 90deg/side ... then why would it not show the dock post above the ball of fish, even if it only reached to within one foot of the centerline ?? It shows fish higher in the water column than the dock post ... and the dock post is a more solid object, so it should reflect a good image. I can understand the fish ball blocking out part of the dock post return signal, but not why the dock post return signal isn't being picked up "above" the fish ball, which tops out at 10' "deep" (in the screen image) but which is actually 10' from the transducer. The dock posts are not more than 50' away from the transducer, else they wouldn't show anywhere in the screen image .... the sonar ping is picking up the bottom half of the posts, so why not the top half ?? Wouldn't the SI ping pick up fish just below the surface, as long as they were within the set distance range .... even though they would appear to be as "deep" as they were actually distant from the transducer ??

... cp

Good deal DonG. The only time I see a dock in that depth of water is when my dock in under water. But, I guess you know this.

Keep the posts coming. I'm glad I posted the snapshot because I sure am learning more about this stuff.

Originally Posted by CrappiePappy

Yeah, I get the distance not depth translation of the ping (I have a DI unit). That's exactly why I don't understand why there is no dock pole image above the fish. Even a ghost image appearing would make more sense than no return signal image at all.

All I'm saying is ... say the transducer is about 1ft under the water, and it's supposed to be shooting out a sonar ping at 90deg/side ... then why would it not show the dock post above the ball of fish, even if it only reached to within one foot of the centerline ?? It shows fish higher in the water column than the dock post ... and the dock post is a more solid object, so it should reflect a good image. I can understand the fish ball blocking out part of the dock post return signal, but not why the dock post return signal isn't being picked up "above" the fish ball, which tops out at 10' "deep" (in the screen image) but which is actually 10' from the transducer. The dock posts are not more than 50' away from the transducer, else they wouldn't show anywhere in the screen image .... the sonar ping is picking up the bottom half of the posts, so why not the top half ?? Wouldn't the SI ping pick up fish just below the surface, as long as they were within the set distance range .... even though they would appear to be as "deep" as they were actually distant from the transducer ??

... cp

It's not pinging at 90 degrees.

What degree is it pinging Justin? And how do you know?Does it have to do with water depth or what?