I took note of the Lifeguards, especially the ones standing in the centre of two pools. They were parading up and down and then posing as if they were on the catwalk. Too tempting for a sketcher!
The difficulty was they didn't stop for long, and every time I was getting somewhere, they would change to a different guard. I managed to get two of them.
This one took his job very seriously:
This one was a little more laissez faire: