Looks like you are doing the four day cruise? If you have snorkeled before and love it, this is fun to do. It is also good even if you are not experienced. We take every opportunity we can to snorkel. There is always something new to see! The bay at CC has no established coral reef, expect only to see fish, not colorful coral or slugs or urchins, etc. The bay has been created by man. There are "trails" marked by bouys above water that you can follow. The below water sites are all created, there are "gold" bricks and treasure. There are large pots that schools of medium sized fish school around, none of the fish are particularly rare, mostly Grouper and Yellow Jack, but beautiful, nonetheless. There are a few non-schooling varieties. A few Butterflies and Tang and Wrasse. We watched an Eel get badgered from his cove by a a few aggressive Tang, once. We have seen a few more unusual species. Hover over the the pots a bit and watch the fish bug each other. Keep an eye out for really tiny fish. The best areas are somewhat far out, easy enough for our younger kids to get to. But, you may have a long, cold, haul to get the kids back in if you follow the whole trail out in the winter months, but you can do it with decent gear and good fins to haul the little guys back in. My 10-12 yo kid did it easily, but I usually ended up towing my little guy (6-8 yo) back in. Wear the vests, then inflate them to let younger kids rest in the water if they run out of steam. Do not touch the bouys! They harbor stinging nematocysts!
Carla