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.