There are several independent companies offering tours of Roatan. There are also several major shore excursions companies that offer tours as well.
We much prefer this way to book excursions than booking through the cruise line - much easier, cheaper, and a whole lot less crowded and regimented making for a more enjoyable experience.
With that said, West Bay Beach has some of the best snorkeling I've ever seen around the world. So if you're into snorkeling or scuba diving, try it there as it's awesome!
Travel Agent/Cruise Specialist w/13 yrs exp and 48 Cruises on 11 cruise lines! Favorites: Paul Gauguin - Tahiti: Uniworld River Cruises - Europe; Celebrity Solstice-class ships; Holland America - 12-nights Baltics & Russia; RCCL - 14-nights Greek Isles, Turkey, & Croatia; Holland America - 14-day Alaskan cruisetour; 10-night Canada/New England cruise; 21 days Hawaii w/7-night NCL cruise; Oceania - 25 days in Asia; more than 3 months touring Europe by train. And many all-inclusive resorts!