"I don't think a 30 - 40 min limit on a saved seat is reasonable as the line for one ride can take you 40 mins to get through. I think for a water park more like 2 hours is reasonable."
But why should those chairs be unavailable for people to use when you are not going to be there in that time? I see the benefit for you to have a home base, but that is not a good use for the park's chairs. How many people can't find seating during that time?
As I later said in my post, I don't believe a family of four needs to save 4 chairs the entire day, but just a couple. My comment that if a policy of no saving was enforced, a 30 minute rule would serve very little value to anyone.
At water parks, chairs are traditionally seen as more than just a place to sit for a while. Especially large ones like Schlitterbahn where you have 3 water parks and take buses between them. The chairs are there for leaving your towels, coolers, dry clothes, hats, sunglasses, sunscreen, and other items you don't want to carry with you from ride to ride. It's also the group meeting place when groups divide up. That's why there are so many chairs at the parks. Probably less than a 1/4th of park patrons are sitting at any one time but there are probably enough chairs for 75 to 90% of patrons.
I also stated that I believe the best solution is self monitoring. When we go to water parks, very little time is spent sitting. Therefore when we drop off our stuff at a chair, we don't pick a prime spot near a popular pool, or one aimed at little kids where adults need to be close by for supervising, or ones with premium shade. We usually find the least wanted, but our stuff there and off we go. When we want a break, we come back and share two lounge chairs between the 4 of us.
When we'd go with a really large group, like 20 or more, we'd do the same thing. Through our stuff on 4 or 5 chairs.
From my experience, lockers at water parks are only used for valuables. That's where we store the cell phone, the keys, and the wallet.