We really liked Dolphins in Depth when we did it! Although there was a lot more time "on land" than we expected. We did this years ago, I think in 2013, so things may have changed since then, but this is our experience: We started backstage where they did a safety spiel and then got into talking about the dolphins and conservation, this lasted maybe 30ish minutes. Then we went out to the public viewing area where they had a roped off an area right up against the glass for us and showed us some of the tricks they had trained the dolphins to do and talked a lot about the training. Finally we got wet-suited up and made our way to the top of the tank. There's a platform in there that is maybe 2 ft underwater we all got on, and were not allowed off of, so there is no actual swimming with the dolphins. Everyone got a turn to use some of the gestures to get the dolphins to do tricks (like waving at you, or splashing you), and at the end they let each of us come up and get a picture with the dolphin. They were very very strict on where you could touch the dolphin for the picture and how you should stand, so not like other dolphin experiences where you can swim with and touch them freely, but still resulted in a fantastic picture! Dolphins are very photogenic.
If you love animals and are ok with taking some time to learn about them, this is a great tour. If you're looking to swim with them and have a lot of interaction, then probably not for you.