copied verbatim....
"from or by means, aid, or use of a sinkbox or any other type of low floating device having a depression affording the hunter a means of concealment beneath the surface of the water"...
section 20.21-HUNTING METHODS...
Thats it...thats all they say....When I've asked in the past the Fed Guys say they interpret that as "the entire body being concealed below the waterline" but I've heard other people say that they've been advised that a certain percentage of the body, (this number is never the same and I've never seen it in print anywhere), must be above the water line.....
This makes sense to me because imagine the difficulty that layout boat mfg's would have making a boat that insured that a "certain %" of a hunters body was above water level....every wt. of user would have to have a different boat in that case, (assuming you wanted the boat to perform the way a layout boat should--chines at water level so there is no wave slap). Make the boat so that a big person would be at that magic % and a little guy would be sticking out of the water like a sore thumb. Reverse that so a little guy would be at theh correct % and a big guy in the same boat would be too deep.....
If I was building something I'd want the FEDERAL GUY that handled my area to see the plans and say "I'm good with that" before I hunted out of it...
Steve