We drove to Nohoch Che'en Park From San Ignacio. Their website has maps. Our family of four including a teenage daughter and son had a wonderful time cave tubing here.
The tour involves walking a mostly-flat distance through the forest and crossing a couple shallow streams. Distance walked depends on the length of the tubing tour you have booked. Plan on anything you bring with you getting wet. You will need water shoes such as sandals with a heel etc. (plastic sandals that will do are available for sale at one of the small tourist retail counters). We are not aware of any place to leave valuables and personal items, so you have to either leave them in your vehicle or not bring them to begin with.
The fee you pay the guide includes the tube, headlight, lifejacket and guide. For a group, the tubes clip together, along with the guide’s tube.
On our walk to where the tubing begins, Walter showed us many interesting plants and wildlife from allspice to withering mimosa to leaf cutter ants and tiny termites that taste like fresh carrots!
The water is cool and fresh and never moves particularly fast. The setting is utterly beautiful in a lush forest. We felt safe at all times.
The caves are long and dark. I have quite mild claustrophobia and never felt closed in. You can see bats sleeping on the ceiling far above, and we never encountered any spiders, scorpions or other critters. Just a lazy river experience inside ancient caves!