I assume the rolling reef closings are independent of pandemic concerns, but I wonder what good they are supposed to do, even assuming that divers hurt the reefs. If the overall number of divers remains the same, the divers who would be going to the closed reefs will go to the ones that aren't, which increases the traffic on those reefs while eliminating divers on the closed ones. When it rolls to the next closure, reefs that had no traffic when they were closed then get more than they would have if no reefs ever closed. It seems to me that over time it's a zero sum game.