I accompanied my son's fifth grade class on their field trip. In one sense, it went off without a hitch. Nobody died and nothing broke down.
We visited a cave, an aquarium, and IMax. The trip took 5 hours of driving and 5 hours of touring/eating. There were so many activities that nobody got to enjoy them. One kid in the group I was chaperoning kept lagging behind because he wanted to stop and look at seahorses, crocodiles, sharks, caves, waterfalls, etc. But there was no time! To hit our time marks we had to walk at a fast clip the whole way.
Of course, we slowed down for the IMax, but after four hours of running, both kids and adults slept through it.
When we loaded the bus to go home--2.5 hours, we got food, a drink, and an extra bottle of water. But the teachers did not want the kids to use the bus bathroom because if they let one kid go, they would all want to go.
I could never be a teacher. Or a prison guard.