I looked at the Dolphins "dive tour" at Epcot for our last year's Christmas trip, but my DD-then 11 (in 2004) was too young. So we went to Discovery Cove instead, where you can be even younger to swim. What a WONDERFUL experience, even on one of the coldest days of the year. Yes, it was expensive, but well worth the $$ just to see how happy she was. It was about $ 750. for the 3 of us - which included a 7-day pass to Sea World as well.
She wants to go again this year, but it's out of the budget.