Yes as Donna mentioned we too are doing the West End Highlights tour. We thought it would be a good taste of the island. I really really really wanted to do some beach trip since this is the furthest south we will be and likely the warmest water, but as I read reviews of the beaches they all sound not that great, at least for what we want out of a beach. I have 2 young children who will want to play in the water and it sounds like they all are rather rocky. So if I'm going to go to a rocky beach I might as well go to the free one right by the port. So our plan will be to do the tour then lunch back on the boat. After lunch we will change into our swimsuits and head out to the beach by port which is also rocky.
If you check out cruisecritic.com they have a St Croix forum with several links to the beaches on the island. Caramolba sounded like the beach is the same as the others but you get to enjoy the pools as well. Personally I can enjoy a pool in MN for much less so I need the beach. I won't be paying more nothing more, which Caramolba sounds like it won't be any better, unless you like pools.