Another nice cave diving video from Slawek Packo. This time diving cenote Outland, part of Sac Aktun system: into direction Hoyo Negro and then a jump to the right.
If your interested in this and other similar cenotes, I can recommend a nice book covering all cenotes in the area called "The Cenotes of the Riviera Maya" from Steve Gerrard (Available through Amazon by clicking the picture on the left).