Just speculating here, but honestly, I would doubt ABD would set up a scuba diving activity as part of the trip. That's really a bit too specialized for a family trip (you need to be trained & certified) and would exclude an awful lot of people. But you might be able to arrange it on your own during your free time.
Guess we'll find out when they announce the itinerary!
(Re-reading your post, it sounds like you may be thinking this is an add-on to a
DCL cruise. From what I've read on ABD's facebook page, it's just the ABD land tours. Of course, there's always a chance DCL might be going there, too. That's certainly not out of the question!)
http://www.youtube.com/watch?v=11rkirrIhrw&feature=youtu.be
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