AMEN!!! I was just thinking this, which it makes sense to have a max wait time for tubes/rafts that are not full. I was coming to suggest the same and glad to see you already did! We are finding that the two water rides we are having issues with are ones where the guests have to wait to have a second rider or full raft in order to run, but then guests avoid the ride because the existing rider who is sitting waiting for people has waited a LONG time (138 min is our current queue time and complaint for long ride with zero people in line) because the ride can't "run" with a partial load.