to make a judge LIKE YOU
Act like you're there to perform, since you really are.
All your gym training, warming up, and pool lessons are irrelevant to an athletes ability to perform well. The performance is 100% mental, as most of the athletes you are competing against, also have been training, and are in shape. So it comes down to a few items to consider, that will give you a bit of an edge, and, hopefully, put you on a path to compete in an elevated way.