Greetings,
I did the GWS dive in South Australia just a couple months ago and it was FANTASTIC!!!
As I understand it, there are only 2 operators that can leagally do trips in SA: Rodney Fox as someone already mentioned and Calypso Charters. Both operate under some failry specific gov't rules on this and both go (essentially) to the same locations for the adventure; Dangerous Reef and Nepture Island.
These spots are 2-4 hours out from Pt. Lincoln and near the Spencer Gulf. They are breeding grounds for the nasty critters and close to a major whale migration route.
They may have the cage floating right below the surface or they may drop it to 20-30 feet depending on where the action is. We were on the surface all the time and the action was non-stop.
There are clearly advantages to either operator depending on your time, how deep your pocket is, etc. I looked hard at both and went on Calypso for a 3 night 4 day trip and we had sharks within 30 minutes of anchor and had them every day we were there. It can be a hit or miss but we hit them every day.
My sense is that the Oz govt watches this closely and monitors the operations. They are allowed to tag sharks and provide info to the govt and universitys for additional research. From what I hear about the South African operators, they are "less concerned" about the sharks as they are making a good show and getting paid well.
I can give you more details later if you are interested. I have attached a small pic of one we saw.
David
