Moving to Bocas del Toro, Panama is the best move I have ever made. Hundreds of expats from all over the world have "discovered" this beautiful archipelago. Beautiful reefs, incredibly low cost of living, almost no crime, no traffic, widespread use of English, and friendly locals have all combined to make this paradise for me.
Panama is also very proactive in terms of encouraging investors and retirees. Great tax breaks and incentives for foreigners to live here.
Finally, being in Central America puts me very close to other great dive destinations. I'm only 20 miles from the Costa Rica border, Belize, Honduras and Nicaragua are only short flights away. Its also quite inexpensive for me to fly back to the States to visit friends and family.