DID is designed as an educational program, not strictly a dolphin encounter. If you are looking for more interaction with dolphins, you may want to check out Discovery Cove in Orlando. DID is not a "swim with the dolphins" program.
However, it is a lot of fun. There is a video and some fun, interactive lecture -- when I did it we had dolphin puppets to use while we learned! It was fascinating to learn so much about dolphins and it didn't really feel "educational." We had a break for some light snacks.
The best (and worst) part was changing into a wetsuit. They have sizes to fit ANYONE (even me

). But wowzers -- they are very form-fitting and don't hide anything.
Then you're off to the top of the Living Seas to a platform. You stand in the water -- which BTW is a somewhat brisk 55 degrees or so. You WILL wake up and feel the chill. The dolphins are invited over and can come to visit and interact IF THEY CHOOSE.
TIP: Book EARLY in the week; I am told Monday is best because the dolphins have no outside contact with visitors over the weekend. By Friday they've interacted with groups all week. It is very rare that they would refuse to interact -- they are friendly creatures.
The interaction is video-taped and you get a copy, plus a t-shirt. The interaction seems brief, but it is great fun. I plan to do it again on our next trip.
Highly recommended. However, if you want more swim time, check out Discovery Cove. That's a blast, too!