i live in fla and had the same question, i have researched this topic allot via these boards, phone calls and books. if you want to get sand from the OCEAN you are supposed to take a boat a few miles and scoop it (diver or big bucket with long rope
). that way there will be no "tourist debris" so to speak. i am still in the planning stages, but, i dont have a boat so i will be buying the sand
oh btw, same goes with the water if you are adventurous enough for that, but i still dont know if i would trust it just because of pollution from boats and stuff imo