Nope, the cool thing about the reefs surrounding BB Caye is that you can dive whatever you want. The variety is fabulous. It is also a great place to snorkel, the week I was there, they sent out a snorkel boat twice a day with the nondivers. I'd say the resort is ideal for new divers.
Make sure they have a trip to Lighthouse Reef planned, that's the best thing ever. (I would not recommend your kids do the Blue Hole though, it's not difficult or technical, but it is a very deep dive).
A few things: You can't swim at night from the docks, there are crocodiles in the water. Honest! They feed them to keep them from coming up onto the beach. Very cool, but a reminder that it is not a good idea to dive from the docks at night.
Bring PLENTY of bug spray. The mossies are absolutely vicious.
Check your bar tab carefully at the end of the week, we found that more often than not, mistakes were made. And careful, I think the Margaritas were $8 each! :wacko:
Be prepared to tip everyone, (bring at leat an extra hundred), the week I was there, they almost begged for tips the last couple of days. They did a great job and deserved it though.
Accomodations and food are first-rate. I would go back.
Have fun! I'm jealous!