That's the whole basis I'm going on, I'm not taking any work from a belizean. I ran into that issue when I was living on ambergris and know that if I want to volunteer its gonna be me doing just that, giving my time and energy for "nothing".
Your visa states you cant work at all, even for nothing. Many folks ignore that and get away with it, and even work for something. Some get caught and then its spendy,and a bad trip.