A couple of other points not mentioned yet:
1. You're going to need a lot more structure on the top pole to tie the two side beams together.
2. An important concept in wakeboarding is loading up the rope tension. If you allow the rope to slide sideways with you as you are cutting in, trying to load the rope, the rope moving with you is preventing some of the loading.
Also, it's probably only a matter of time before someone adds this one to the ugliest tower award thread.