I've done it 3 or 4 times already, it's a great experience. It has been a couple of years since I did it last though, so I don't know how much they charge now and what is included.
Back then, you only had to bring bath trunks, everything else is provided, I brought my own dive mask, as I have corrected lenses in it and my own dive computer.
We met at guest relations outside Epcot, the CM checked our open water certificates, one time, I forgot to bring mine, they called the dive organisation and could check with them that I'm certified. Then he took sizes for the wetsuit and the fins as well as how many weights we approximately would need.
Then we went backstage and walked to the Living Seas pavillion. We went into a meeting room where they showed us a short video about the pavillion and then gave some instructions. Then we went to the changing room where everyone received key for a changing room where the wetsuit and the fins already were waiting.
Once changed, we then went on-stage into the pavillion, it was quite funny to walk through the pavillion in a wetsuit with all the guests looking. We went to the aquarium observation deck and entered a backstage staircase in the center of the observation deck and climbed on to of it. There you get to see all the lights and catwalks above the aquarium. There we got into the water and CMs helped putting on the air tanks.
If I remember correctly, we were accompanied by 2 divers plus a photographer with a watertight film camera. First we did a tour through the aquarium single-file for about 10 min. or so. The guide showed us some interestings sightes like the old sponsors lounge above the Coral Reef Restaurant, then we swam through a cave like coral structure and finally each one got to enter the dive bell.
After that, the guide split us into parties of 2 and we were allowed to explore the aquarium on our own. They gave us about 15 min. for that then the dive master banged on his tank to let us know that we had to go back to the rope that showed where we had to dive up to exit. Not sure if we did a decomp break but I don't thinks so.
We then went back to the changing room to change into the street clothes again and then went to the meeting room again where we were shown the video they took while we were in the tank. We also got a video tape to take home was well as a certificate.
While park admission is not needed and officially not included in the tour price, at the conclusion of the program, we were just escorted back onstage at the Living Seas pavillion and could enjoy the rest of the evening in the park for free. However, if you have family or friends who want to watch you from the observation deck, I think those will need admission.
