[rottal]

If you are going at night throw a small/medium sized cyalume light (or chemlite, light stick, whatever you want to call it) inside your bottle before you cap it...you will be able to spot it very easily after the sun goes down---they will glow like chinese lanterns. only do this on remote water though, if there are people around they will be chasing your jugs all over the place out of curiousity...