We bought a knotted surf rope with removable sections but we use all of the length it came with and the reason is that then you don't have to get so close to your rider to toss him/her the rope. For us, it has nothing to do with where the pocket is. We come up 10' or more behind the pocket and just pull ourselves up to it then toss the rope in. If you are using a thin rope that is not as easy on the hands to grab, then I could see why you would want to minimize the length of the rope.