$105 for a half hour with the dolphins seems expensive to me. Our family will be going to Discovey Cove (SeaWorld) when we get back from our July 6th cruise (Shhhhhh, don't tell the kids - it's a surprise).
For about $200, we spend the whole day at Dicovery Cove swimming with the dolphins (also 30 minutes or so), snorkel in a colorful reef, tropical fish and among stingrays, explore a shipwreck, swim in a tropical river with waterfalls, and enter a free-flight aviary, etc. Yes, it's more money, but we spend the entire day there and it includes a full lunch.
It seems strange to go on a cruise to where these things are naturally found and then spend time at a recreated tropical paradise. Oh, well!
Sorry - no personal experience. That's going o change in about 1 month.
Good luck!