Topic: PVC Condo's

[TarponFly]

I have yet to look for my condo's due to I have yet to get to that lake. A buddy said he was out where we placed them and his Lowance SI cant see them. Does the side scan pick up plastic and stuff like that? Or is it invisible? He said he drove around for 45 mins trying to find them.they were chained to a tree when the lake was low. So there is no way in heck anyone could have snaged them and moved them.....

[RGecy]

You should be able to see them but you may need to slow down to 1 or 2 mph while scanning.  The pvc is small and round and deflects the sonar like a stealth plane does with radar.  It is going to have a very low sonar signature so the more pings you can put on it in a short distance, the more likely you are to see them.  You will most likely only see a fine line where the pvc is, but the shadow should be more noticeable.

There are some images somewhere on here that show them.  The user had put a reflector on the top of the pvc trees to help see them better with the SI.

You may have better luck seeing them with 800khz vs 455khz.  If you do get out, make sure you take some snapshots and post them for us to see.

Good Luck,

Robert

[Moose1am]

I put 5 or 6 PVC crappie trees in the water I fish.  These are ten ft tall and have ten ft long branches. Ten branches on each ten ft tall tree.
 
I used 4" OD pvc pipe for the trucks and then added concrete to the base and some float material to the top and then capped it with a 4" cap.  The side branchs are 1" od pvc pipe.
 
I use a Humminbird 898 C SI unit and had a very hard time seeing these. I had five of these trees in one spot that's not more than 25 ft deep.  I eventually got a good picture using DI. But I had to go right over the top of the PVC tree to get the picture.  I could see the branches and the tree truck well. 
 
So either they don't show up good on the si or someone or something moved them.  I doubt that the latter is true as they are not going to float away and there is no current in this lake.  The ground were they sit is faily level with a little slope towards deeper water.   A few of them may be laying on their side.  I have looked for them using an older LCR 8000 Humminbird Sonar unit and can't see them on this unit very well either.
 
They being round and made of of PVC Plastic probably don't reflect the sound waves right back to the transducer and instead the sound waves reflect off at different angles as they hit the rounded pvc pipe.  So the transducer can't see the echo returns very well.  Now if the PVC Pipe was flat and at a perfect right angle to the sound waves they may reflect the sound waves back much better. Or perhaps the hollow pvc pipe absorbs the sound waves more than reflecting them. I really don't know the answer. All I know is that they are hard to see on the depth finder screen. 
 
I have gone over this area at least 10 to 15 times and made multiple passes over the area from different directions.
 
I did find a brush pile that's made out of wood and it shows up easily on the SI, DI and regular 2d sonar screens.

[sonar2000]

The corps of eng put pvc trees in the lake and we ran sonar to check them out. Very sinmilar to your trees.  SI has a hard time seeing them but Di does a better job.  All as you indicated with yours.  Round PVC will let the signal slide around the pipe and not reflect as well as a flat surface. We have suggested the next trees have pie tins for leaves to see what that will do...
Chuck

[Rickard]

Another thing, PVC and most other resins are to some extent 'transparent' to sound in a water environment. That's why sound can be transmitted and received through a polystyrene hull. If submerged PVC pipes are filled with water, they should be hard to see with sonar.

Rickard

[Triton Mike]

Triangle shaped PVC condos.  This is with the old 987SI.  I can do much better with the newer units .



Mike