You would think they would enforce the 30 minute rule. Perhaps then people would think twice about putting their towel on a chair early in the morning just to save a chair while they do everything except use the pool area until they're good and ready. One time I noticed two chairs being reserved with towels and a book. I timed it for another 45 minutes and then told a pool attendant about it. He took the towels and books off the chairs.
About 10 minutes later an elder couple returned to their chairs only to find another person sitting in them. I felt a bit bad about it, but rules apply to all. I told them the pool attendant took their stuff because they were gone over an hour. Maybe more people should do what I did. Reserving lounge chairs is a pet peeve of mine too.