Look in the phone book under diving for a local scuba shop that provides instuction.I would ask them about the open water referral program. This is where you take the clasrom and pool portions of you training at home and then complete your certification in Belize by doing four open water dives with an Instructor. The cost for the open water dives is approx US $225. Ask your local dive shop what they charge for the classroom and pool portion. I did mine in one weekend! Another option is to take a resort course in belize, you can dive after a little work with an instructor, but you will not be certified. Try this link www.barefootwatersports.net
They can give you all the info you need. Good luck!!