Here is an example of a simple low cost way to add structure to your favorite fishing spot. I believe the tubing is mostly invisible to sonar, so all that should show to others is the block. We placed a bent nail in them for a loop so you can lower them down with a hook on a rope, when they hit the bottom it pops right off. We are placing them in sets of 3.
A 80 lb bag of concrete will make 7 single hole cinder blocks. The 1/2" irrigation tubing is $8.99 a 100'. You can make 4 per roll. Each block is 97 cents. Total cost is less than $4 each.
Modified by rudapa at 3:33 PM 12/24/2009