Which one has the pipe?

So the variations are very interesting indeed. I would think the one most likely to stay open will be the one which reaches the surface with the greatest associated water velocity. There is a de-icer that is a available that is built on this principle of moving water to maintain open ice.

I think the pipe idea is a good idea because I think it make the water moved more efficient and it concentrates the energy over a smaller area. A bigger pipe over the quad might even be better. Anyways so far so good!

It isn't what we don't know that gives us trouble, it's what we know that ain't so - Will Rogers