unfortunately that is the way Professionbuddy handles flying coordinates near water, for some reason the author hasn't seemed interested in fixing that. I was working on using walking coordinates so that you don't run into that problem, but the problem with that is everyone will have to have the same starting point, which they don't depending on when they stopped questing in Vash. I was working on one that works with the cave, if that's your starting point, i can finish that if you'd like, but that's about all i can do.