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

I think with all the new stuff coming out that I will stay with my Gen 2 units. I caught fish off of this dock yesterday..

See the fish ,catch the fish, I'm with you . I'm a HB guy no need to upgrade if it's still working. I'm still killing deer with 15 yr old bow, the deer are still dying no need to speed thousand on a new bow can't kill them anymore lol. Nice picture

Dock ??? What dock ?? All I see are trees and a ball of fish

(or are those "match" shaped images the dock supports/posts ?? And if so, why do they not go all the way up to the prop wash strip ??)

... cp

Originally Posted by CrappiePappy

(or are those "match" shaped images the dock supports/posts ?? And if so, why do they not go all the way up to the prop wash strip ??)

... cp

I would guess those are indeed the dock posts starting in the left water column at about the 18ft SI Range line ...

This would mean the dock was a little over 18ft from the xducer before the sound pulse actually 1st contacted the dock posts ...

Echoes of a vertical structure all the way to the centerline would mean the xducer would be right up against the dock posts = shorter distance to xducer ...

Rickie

Thanks for bailing me out, Rickie.. Gene usually has to do that..

Originally Posted by rnvinc

I would guess those are indeed the dock posts starting in the left water column at about the 18ft SI Range line ...

This would mean the dock was a little over 18ft from the xducer before the sound pulse actually 1st contacted the dock posts ...

Echoes of a vertical structure all the way to the centerline would mean the xducer would be right up against the dock posts = shorter distance to xducer ...

Rickie

OK ... I can grasp that. But, why would the fish or trees show up "above" the dock posts ?? If the SI signal is 90deg/side, why wouldn't it show a solid object (that rises above the water's surface) reaching all the way to the center line/prop wash image ?? Don has the range set at 50' ... so if the dock is around 20' away from the transducer, it would seem that it should show the posts going all the way to the surface (or at least a image above the ball of fish).

Had I only seen the screenshot, and not been told of a dock being there, I would never have suspected there being a dock in the image ... and probably figured the "matchsticks" images to be tree trunks or posts from a dock that no longer exists.

... cp

Originally Posted by CrappiePappy

OK ... I can grasp that. But, why would the fish or trees show up "above" the dock posts ?? If the SI signal is 90deg/side, why wouldn't it show a solid object (that rises above the water's surface) reaching all the way to the center line/prop wash image ?? Don has the range set at 50' ... so if the dock is around 20' away from the transducer, it would seem that it should show the posts going all the way to the surface (or at least a image above the ball of fish).

Had I only seen the screenshot, and not been told of a dock being there, I would never have suspected there being a dock in the image ... and probably figured the "matchsticks" images to be tree trunks or posts from a dock that no longer exists.

... cp

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

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

Rickie, I hope you are keeping a book on SI/DI questions & answers. If you are, please save me a copy..

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

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.