Of course, it's really up to you, but do you want to spend the whole day dragging around a razor, then find a restroom to actually shave in the afternoon while you're in the parks? Even at a water park, I wouldn't bother.
I'd say there's enough people around from a variety of countries (and personal grooming habits) that i wouldn't worry about it, if it were me. Of course, if it really bothers YOU, then go ahead and do what you're comfortable with, but I wouldn't worry about what other people thought.
Personally, however, I get my legs waxed before I go on vacation, which means I don't have to shave at all while i'm there. Waxing duration varies, but I can usually go at least 2 weeks, sometimes even more, befoer needing to do anything (then I follow up with my epilator, since it's only a few hairs that grow back at a time).
Just a suggestion!