While we were in a longer line, and I happened to look down into a pool and see the lifeguards. Suddenly, someone landed in the water and started flailing. After a few seconds, the lifeguard blows the whistle, grabs a flotation device, dives in the water, and then I notice she’s smiling and going slowly. Initially, she gets there and helps the person. Then she blows the whistle again. I realized it was a training exercise.
I asked later if this was something they did regularly. They said, “Yes, but we never know when it happens.”