On our recent Caribbean cruise, we didn't want to spend all four port days diving. We did end up renting equipment one of the days though to snorkel, and it was so much fun! Apparently, the diving in Honduras is amazing, as it is in many places down in the Caribbean, but the snorkeling was cool too!
One thing we did learn after snorkeling is that sunscreen kills reefs. The reef we were at was about 90% dead because of the tourists' sunscreen. (Ours included!) But you can buy reef safe sunscreen. Next time I go swimming, snorkeling, or diving, I'm going to make sure I have environmentally friendly sunscreen!