The musical show featured three of Shamu's established friends: Arthur C. Turtle, O.P. Otter and Sir Winston Walrus. They were costumed actors with moving mouths. I'm not sure how they pulled this off, but it was nicely done. The set was a giant coral reef (the reef itself had blinking eyes) filled with animated sea life, including eels and polyps. I'm not sure if these were puppets, animatronics, or a mix of both. There was a huge video screen behind the actors that displayed movie and animated sequences.
This was geared toward young children, and I do remember some older audience members getting up and leaving during the show. Unlike most of Sea World's shows, this one was indoors and had air conditioning. Being in Orlando, it seems like this had the potential to be one of the most popular attractions at Sea World. I'm not sure when this closed.
The "Undersea Fantasy" photos and this park map, featuring the animated Shamu and his friends, are from my visit to Sea World in 1987. My, how the park has changed!