They recently made some changes to the way they "load" the Shark Reef. You now have to wait in "batches" of 15 or 20 people (or more) for the lifeguard to go over the use of the snorkel and mask. They play a game of "Dory Says". They do this EVERY time you go. They do not allow you to skip it, even if you just got out and got back into line.
That said, it is a neat experience and a great way to cool off on those HOT days when even the pools are warm.
Ted