Can depth finders "read" pvc?

My uncle claims that depth finders cannot pick up on plastic such has pvc, therefore he has sunk some to fish on thinking no one else can see it like they can see wood. Is this true? If so what about empty five gallon buckets? I am thinking about drilling holes in the buckets and putting a rock or busted up block in the bottom of them and dropping them over to make a "invisible" stump field.

Most units can show pvc.

PVC is solid enough to show on the majority of sonars, fish however are not... except for their air bladders. When you mark a fish on sonar, you're not actually marking the fish... you're marking the air bladder! Sonar doesn't work through air and fish flesh isn't dense enough to return a good echo... guess what you're picking up on the sonar when you mark fish?

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Originally Posted by GCD

PVC is solid enough to show on the majority of sonars, fish however are not... except for their air bladders. When you mark a fish on sonar, you're not actually marking the fish... you're marking the air bladder! Sonar doesn't work through air and fish flesh isn't dense enough to return a good echo... guess what you're picking up on the sonar when you mark fish?

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Sonar does work thru air, but not efficiently with this type transducer. Sonar ranging is common in motion robots.

FYI.

I have sunk a great deal of PVC and I can see them on the H'bird quite well. Actually the hardest thing to see with SI is small limbed brush on a hard bottom. I do not think you can hide anything from traditional sonar.

My theory is most pvc is small diameter and built verticle so you will have less area to bounce signal back. Wooden stakebeds built short with few small,wide spaced stakes doesn't show up as well as horizontal brushpiles.;)

PVC is easily found with modern Fish Finders. See the pics below. These condos are all pvc.

http://grangergang.com/photos/898_SI/s00030.jpg

http://grangergang.com/photos/898_SI/s00031.jpg

Wow, that is an amazing FF!!

By the way this is what one of the condos looks like before i dropped it. ONly this one has a wooden pole.

http://grangergang.com/photos/Condo1021.JPG

This is what they look like on my cheap FF i have on my Trolling motor.

http://grangergang.com/photos/Condo1021_Sonar.JPG

So Pvc is seen from a standard sonar.

Here is another one that is ALL PVC!

http://grangergang.com/photos/Condo.JPG

Here is what it looks like on my Old Sonar (Garmin 240) that I replaced with my Humminbird 898.

http://grangergang.com/photos/Condo2_80.JPG

Salty, what is the center post made of?

Peke