Ric Maniac - Your 100% correct. A tanks footprint is more important than the total gallonage of water of which it holds. A 2,000 gallon tank could be 10" wide, 10" high, and say 50' long. Yes, it may be 2,000 gallons but no Shark would ever be able to fit in that sized tank. I have seen 350 gallon tanks that are not big enough for sharks, simply becasue they are tall and skinny. Width and length are the major dimensions to take into consideration when venturing into keeping elasmobranches.
Mike22Cha - Coral Cats, Marbeled Cats, ect May be able to live in a 180 gallon for a few months. But they need atleast 250 gallons, perferable 300 gallons for life. Even this is cutting it, when you see Sharks in the wild, or in large ponds / tanks you will never be able to get your self to shove one in anything less than 500 gallons for life.
As for SWF selling Sharks & Rays, I think what they are doing is very proffesional and ethical with both the Sharks and Hobbiest best interests in mind. I am all for having to prove your credibility before purchasing a species which is a long term commitment. People need to understand what they are doing, this will stop impulse buys from happening, and will help the hobbiest understand the needs and requirments of Sharks in the home aquaria.