The port itself is very nice, well put together. We went to Irie Beach (Cornwall Beach) and it was pretty disappointing. $100 / person for 45 minutes on a sweaty bus, just to get to a crowded beach for 3 hours was not worth it to me. On the one hand, the food was really quite good, and if it had been in the $50 - 60 / person, I really wouldn't have much to complain about.
UNBELIEVABLE - best time / money we spent on cruise. it was the "Double Snorkel Site" excursion, and everything about this was fantastic. The boat crew, the free drinks, and of course the snorkelling was amazing. They managed to find us a ray and a sea turtle to watch, and the coral was gorgeous and well up to the hype. Definitely would do this again in a heart-beat.