My family just booked our first week-long cruise, it's with Royal Caribbean; to Grand Cayman, Cozumel, and Costa Maya in December. We were wondering what excursions should we book and which ones to stay away from.

Wow! There are many options and your question is very broad. What kind of things are you interested in doing? Once we have a better understanding of your interests, posters will be able to provide you with suggestions.
Nancy

I've recently booked a week long cruise for my family (2 teens 17 & 15), my husband, and myself on Royal Caribbean. Sounds like I picked the same itinerary (Belize City, Cozumel, Costa Maya, & Grand Cayman). We're sailing 12/4. I've heard that the ship excursions tend to be overcrowded. I found some info. at shoretrips.com, but don't know how reliable it might be. There are so many options that it's a little overwhelming.

Shoretrips is a good, reliable excursion company. They contract with local guides, who from my own experience are very good, and often have smaller groups than on the ship's excursions. Sometimes they even offer a tour that the ship doesn't, perhaps with a particular theme or activity. If you booked your cruise through a travel agent, please allow your TA to book anything you decide to do on Shoretrips too, as they do work with TA's.

Thanks Karen - I appreciate the feedback. Everything about Shoretrips looked very legitimate, but you never know these days....I'll definitely get in touch with my TA.