But in refuting my original statement you took it out of its original context, which was that of adult marine animals in captivity. If you see keeping a juvenile shark for a period of six months as a measure of the viability and success of keeping this species in captivity, then that's where we're seeing things differently. I'm sure there have been thousands of instances of great whites being reared from a young age in captivity, but this doesn't go any way to prove
The fact is, and this is scientific fact, not my opinion, is that sharks swim in circular patterns to basically sleep. The larger the shark the larger the circle, and the fact is that most are far too small. Safety of staff and other species would be of little concern to any properly designed facility, which goes back to my original point.
I should add that at Sea World here in Australia they have a facility with a main pool approximately 200ft in length dedicated solely to large sharks named Shark Bay. They have several tiger sharks currently on exhibit which would be around the 10-12ft mark (they grow to be about as large as great whites in these waters) but they haven't been able to try a great white for the simple reason that none have been caught in local waters since it was built. I suspect one day they will get one in and if there's one facility that has a chance of keeping great whites successfully, it'd be this one.