Dolphin Encounter vs Dolphin Extreme Swim in GC

[Docmom]

We're going on our first DCL cruise as a family in April. I wanted to do the Dolphin Encounter in GC as it's something I've always wanted to do. Now DD8 says she wants to do the belly swim which looks like is only available in the Dolphin Extreme Swim. Not a huge price difference but for a family of 4 enough for me to ask if it's worth it. Has anyone done either? For the extreme swim how good of a swimmer do you need to be as she's not a great swimmer yet? Is it fast or a more moderate pace? Also on the Wonder 5 day from Miami is there enough time to do the dolphin/turtle farm excursion and the shipwreck snorkel? The encounter plus shipwreck would cost about the same for both as the extreme swim. I can do online check in at midnight Wednesday so wanted to consider all the options beforehand. Also are these tours sold out quickly? Thanks for any advice on these.