It's really good that you'll have DAN coverage while you're diving in Belize.
However, don't forget to say to your dive shop here in San Pedro a big "YES" to the option of paying a dollar or two more to cover local dive chamber insurance for each dive you do during your stay. Not only does the slight extra cost cut down on paperwork and worry in the event of an incident, it also goes to a very good cause...the safe and professional running of the Hyperbaric Chamber here on Ambergris.