my true word of advice. It seems really idyllic now that Atlantic put all this emphasis on service, thats great. But when it came to my exams I felt extremely under prepared academically, despite all of the hard work I had put in. At the end of the day, it's your high school, your 6th form college in a way, and its possible to do lots of wonderful extra curricular things at the same time as getting a great degree.
I dont want to seem negative, and, as I said in my previous post, UWC is a wonderful balanced education that I have never regretted doing. Don't underestimate the importance of national groups e.g. in maastricht. At my school (AC) all the chinese grouped together (bar a few), all the latinos were one huge national group too. You will appreciate the support of having other native english speakers, because non-natives after spending all day studying in that language, just do not want to chat in English especially in teh first couple of weeks when everybody is adjusting!
Anyway, my main point is service is great, but academically I felt that I should have gone to another UWC/international school in general because when it comes down to it, you are competing for university places against everybody else who does the IB including reams of japanese, indians, koreans, chinese, really really intelligent driven people, and sometimes being a lifeguard just isnt going to make that up, you know?
Also, for marine conservation, apply for Pearson!
Finally, in the interview if you havent had it yet, just be yourself. One girl I know was incredibly over enthusiastic about everything and perhaps over embellished her achievemnts. She got sent to the US and was just incredibly miserable for her two years there because she couldnt really connect to other people because they didn't really share the same inetrests.
I hope my advice isnt too negative, but trying to be honest. Best of luck!