Danny is going on a trip to the Kaieteur falls in Guyana. How cool is that? Lucky guy! He asked me of all people for tips on shooting waterfalls. Trust me Danny I'm the last person you should be asking for advice. I am really just a novice and totally suck at trying to explain the technical stuff. (Code for I don't know what I'm doing half the time.)
Anyway if I were fortunate enough to be going on such a trip this would be my advice....read, do lots of research, take practise shots of running water, even water from a faucet could stand in and get yourself prepared. Click here and here for great tips from folks who actually know what they are doing.