Sir, at CJ, due to ODNR and COE restrictions until recently we were REQUIRED to rig the "C" trees as laydowns once they water logged, plus we had a "hidden" agenda to create semi horizontal spawning cover to help CJ`s struggling yellow perch population to explode (which incidentally seems to have succeeded VERY well ). Generally we would get "2cnds" blocks with mars, cracks on 1 end, chips, ect at about a 6 or 7:1 ratio of 8" for the majority and 10"ers for the extra tall 1s. An 8"er weights 32 pds, a 10"er weights 40 pds, and have sank a 8` "C" tree on top of a 10" brush block ("BB") called a "super". Admittedly awkward to handle, but with 4-6` osage orange or locust limbs that will last 15+ yrs stuffed into the block, WORTH it. The 1 critical thing: when you secure them make CERTAIN the tree trunk is cleared of lower limbs on 1 side and secure both ends of the block TIGHTLY to the trunk ! When you get done, lift the cut end of the trunk; if the block has ANY slack or is loose at ALL, RETIE it. In areas with wave action (windward shores) or current this is CRITICAL...and YES, they will work ! Try putting them in lines shallow to deep; a NICE touch is a couple of PVC attractors on the deepest ends...(evil laughter sound effect here !) TRUST us...After all, we`ve only placed 2,000+ of them...so far.