As for the rock idea we have tossed around several ways of making this. I think the best idea was thrown out there by Edward Lindsey. His thought was to take a sheet of cork, cut into two equal squars stack and glue. Bandsaw a top view and rasp into shape. It can be left natural( talking black cork) or painted. Anchor through a large eye bolt from underneath one edge to allow for current and wind drift. Another idea was to stack foam thick enough and put a bottom board under it to run the eye bolt through. Same shaping. It has to be big enough to hold three full bodied Harli's. Drill holes into it and these could be reinforced with conduit. Here is where I am for now. My mount has not come back, and I do not still have a study bird.
HOLY CRAPPIN CRAP....whenI called you I never expected you to say yes and then after you said YES I never expected to get them for this season......I knew I should have asked for FIVE instead of three......
Fred and I talked today and he said he saw the PERFECT rock at a taxidermist....way bigger than we need and only weihged about 5 lbs.......he's checking on that cause "light" is going to be important so that the "rock" doesn't submarine in the current.....he had a super idea on that one as well....I'll save it until after the first test......
a molded fiberglass which is hollow on the back side. I would suggest using one of those and using a single layer of cork or foam as a float/base. Might also want to experiment with the anchor attachment. A three point "harness" of small chain coming together near the center of mass and hanging down about a foot or so, might work better than a single attachment point. Don't know for sure, just thinking out loud. I'm thinking the weight of the chain (which is variable by length and size of chain) might act the same as a weighted keel would on a decoy to keep it upright.
If the rock is hollow on the back then you could epoxy a bottom board or bottom cork or bottom something on. It is going to take some playing with. Steve you said you needed them. Glad you did not say five. Then You would be wroking on Two Rocks
Jason.
If you want to give it a try, remember that I've got a bunch of 2" thick blue poly foam panels out behind my shed. A lot lighter than cork and easier to cut/glue up.
Give me a call.