What to do at a swim meet?

Unless you are at pool level, you are usually dry., or drying off.

Reading a book is fine. Mind you, cheering on your teammates who are racing is better.

If you're on the team you shouldn't think about bringing a book, you should be cheering on your teammates and boosting their confidence and actually being a part of the team. We aren't allowed to have homework, books, or electronics out (we can listen to music, but no texting or twitter or anything) even if we aren't competing in that particular meet, and we need to be down at the end of the lane cheering on your friends. Giving someone a pep talk before an event they're nervous for is going to do your team more good than sitting on the bleachers reading.

Helping your team mates get ready for a race, be a counter for the long swims, cheer on your team mates, help your coach, etc.