Also, when making the RL whoopie, remember to leave the tail end (the one with the fixed eye) longer than normal. You don't need the large range of adjustment here. To visualize it a bit better, make it so that the shortest the whoopie can get is 85 - 90" or so. Then the largest it can get should be in the 120" range.

I haven't done one up myself yet, I'm being lazy and buying one from arrowhead equipment, but I think 14 or 15 feet should get the job done...