Crusin 
I have a group on this sailing as well, and I've been counting down the days!
Another option for locating items of interest is checking the websites of each Island we will be visiting. What I've been doing is going to each islands website and checking for all activities available at that location they may interest us. My big thing this cruise is locating scooter rentals on each island...(something new this trip)
we have tried using the excursions but find they limit our ability to see the island as you end up in one sport. We have been renting cabs at the pier and this way and we not only see more of the island but we have the opportunity to do/see much more while in port. You can spend some time at the beach and if you're lucky you end up with a really knowledgable cabbie and a more personal tour of the island.