Thread: PVC cover

Sonar detects differences in density of structure vs the surrounding water ...

PVC (when filled with or surrounded by water) has a very similar density as the water itself ...

Some sand the PVC to accelerate algae growth on the PVC ...

Some trap air in the PVC to create the different density factor ...

Others use PVC exactly for the reason you stated = it's harder for others to find ...

Rickie

Thanks Rickie, good explenation. I think I`ll add some wood or trap air in them to help me re-locate. You did say traping air may just be the answer?
See I gps them but where I put them at times there is current and somethimes, I think it could move or knock them over so finding them again would be very benifical to me.
Thanks Again,
Steve

PVC at the base of a drop.

Originally Posted by steve telinda

I think I`ll add some wood or trap air in them to help me re-locate. You did say traping air may just be the answer?

Air has a different density than water ... which is why the fish's air bladder is believed to be the contributing factor of fish showing on Sonar ...

Rickie

Rickie, the picture you sent reggarding the structure being pvc, is that one with air traped inside like you suggested?
If s0, I could seal both ends and hopefully have the same readings once sunk?
Thanks again

That pic is Justin's ...

I'm not sure if he trapped air inside his PVC structure ...

Rickie

This is one good reason to have GPS it lets you know that you are within about 3 meters from where you dropped the fish structure(PVC, brush, wood,etc.) Then you just go back to that concordance and look for the fish that show up around you structure on sonar to pinpoint where to fish it.

Originally Posted by rnvinc

Air has a different density than water ... which is why the fish's air bladder is believed to be the contributing factor of fish showing on Sonar ...

Rickie

Rickie ... I've always heard that as well, BUT ... then how does one explain this DI screenshot :



seeing as how it shows "fish" outlines and not simply air bladder density differences ??

Could it be the different megahertz frequencies between 2d & DI/SI ??

And as a side note : if you cap the PVC pipes to trap air (or even add wood) ... wouldn't you also have to use more weight to hold them down, to compensate for the buoyancy of the air/wood ??