We did this in March 2022 booked through NCL. My understanding is that this specific cave/cenote is only available as a cruise line excursion, and not available for independent bookings. It was amazing. Like others said, the best excursion we did on the trip. It was also extremely well run and organized. All gear is includes as is lunch (they even provided a hair tie for my daughter when we realized she had forgotten one). Even though it was a cruise line excursion, the groups were small and there are several routes through the cenote so you don't even see the other groups. I don't normally buy the tour taken photos, but I did for this because 1) you can't take your own and 2) it was so cool.