Just got back from doing this tour. It's not a bad tour, but what you get isn't quite what is indicated on the website. Basically, it's a very expensive speedboat ride. Since it's a "Carnival Special", it's only for those arriving to La Romana on Carnival, which is usually in port for only 6 hours. They whisk you away quickly into pre-reserved taxis for a 15-20 minute ride to Bayahibe, where you pay and get into groups for the speedboat. The boat is small and packed with people. It's a bumpy 30-40 minute ride to Soana Island. You have a pretty good buffet lunch once you arrive and total, (including lunch) have about 75 minutes on the island. The island is beautiful, not very crowded, with a small beach and plenty of palm trees/shade and chairs. You then get back into the boat and ride 15-20 minutes to a small sand dune which is waist deep and everyone walks or snorkels around the small area to find the 15 or so starfish that are there. There is nothing else to see except sand. Then it's back in the boat to return another 20-30 minutes where the taxis are waiting to take you back to the ship.
So here's the time breakdown:
Speedboat total time - 65-90 minutes
Taxi - 30-40 minutes
Starfish - 20
Time on island (including lunch) - 75
So you're on the boat longer than anything and the entire trip is 3 - 3 1/2 hours.
Website also says you sail along the coast of the National Park and the guide will explain you some of the sites and history. This doesn't happen. The boat follows the coastline, but it's far out and no guided talks - it's way too noisy for anyone to eve talk.
Website says on the island, the guide will take you snorkeling at the pier - this doesn't happen.
Website says on the way back, you go through the Mangroves and guide will explain this. The boat takes the same route as it did on the way there - no Mangroves, no guided explanation.
It's not a bad tour, it's just very rushed and you spend more time on the speedboat than you do anything else and for that, it's an expensive speedboat ride.