Alex and I discussed "warp speed" yesterday. I had to leave right after we got the piece set. He bolted it in place and he and 4 year old Landon tried it out...fast...yep. Alex went head first and tried to hydroplane...that's what our first concern is...he could not make it happen yet...he's good at understanding how to arch/plane out, as in a racing dive that swimmer's do. He could not make his body plane...what he didn't try yet was having a steep enough entry angle that you auger down into the water and Aquaman/torpedo too far...that will be the next test.
Our plan is to try to wring out planing on the water and under the water as we go to see if gravity and common sense says, "Enough!". And you are right, Sean...the elbow, which may be several pieces, depending on how gradual we make the turn, and two more 14 foot long sections are still part of the original plan.
We are working on a way to have an enclosed climbing area up to the entry point so that the exposure is minimized...don't like the idea of free climbing exposed ladder/stairs.