Our first cruise was also the land and sea package. I booked the dolphin swim on my own from my family of five. The excursion through
DCL is the Dophin Encounter, not the swim. I booked directly with the company on line, I think the site is
www.dolphinswim .com.
The difference in these two, besides expense, is that you get into the lagoon with the dolphins and they do some pretty cool things with you. This takes place on Blue Lagoon Island, so I'm sure you could arrange to stay there and enjoy the beach as well. There should be information about that on the site as well.
If I'm not mistaken the Wonder stays in port until like 10PM, so you have all day to enjoy. We actually went in the afternoon. Spent the morning on the ship, then took a cab to the ferry port, enjoyed this most incredible experience, then back on the ferry and a water taxi back to the ship. There are probably multiple times you can book your swim for and either play on the beach before and after the swim. You'll have more than enough time.
We loved this experience, and buy the video that they take, it has been well worth it. My kids have even taken it to school for the teachers to use when they study dolphins.
I hope this helps, good luck with the planning. Let me know if you have any questions that I might be able to help with!
