I was just in Roatan last week. My friends did the zip line and loved it. I stayed on the beach at Tabayana. I was not nearly as impressed as what I thought I would be. Several from the ship rented a tour guide for the day. This guy took them around the whole island, took them snorkeling in a private area, etc.. They had a blast and it was really inexpensive- I think he said including tip it was about $100..and he tipped him about $50.00. So, the zip line is great, but I might try another beach option next time. Roatan is a very poverty stricken area, so don't be shocked at what you see when you first start going around town. It's a third world country and that' s the sites that you will encounter.
Enjoy your cruise. We had a blast! Bring bugspray for Roatan!!!!