Lifeguard personal firstaid kit?

Im a lifeguard at my local pool, and im not too confidant about the first aid supplies that are kept in the office. They really just have the basics, like band aids, neosporin, burn relief pads and thats about it. I also want a personal kit i can keep in a fanny pack so i dont have to go to the office to get medical supplies during an emergency. Could anyone give me a list on what might be good supplies to have in a small fanny pack sized kit?