Hopefully this photo turns out or this will seem like a real dumb post. This is what I developed as portable crappie cover and it works very well.
Ken
I take a piece of mill canvas 16' long by 1' wide ..fasten a float on the top , 2 2x6's wood , 1 of foam and screw it all together at the top.
At the bottom I use an old brake rotor... slide the canvas thu it and cut a slot and push a length if ready rod thru so that it cannot put back out.
Along the length of the canvas I cut slots and push spruce bows thru.
Very simple to make , simple to put in the lake , simple to move to a new spot,and simple to pull out.
Ken