The company that installed my system used poly pipe similar to Mr. Willy's. They formed a "mat" about 50'x50' out of plastic snow fence by zip tying it together. Coils of the poly pipe were spread neatly across the mat, layed flat, and zip tied to the mat along with concrete blocks for weight. The whole contraption was drug into the pond. The installers said they prefered to do it in when ponds were frozen so they could built it in place and just let it sink. The installers also said they were putting in a 100 ton system to heat the new horse arena and stables at the Fairgrounds. This system would use 20 of these "mats" sunk in the nearby quarry. Just thought it was interesting.
"The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge." Stephen W. Hawking
