One of our DMs was out spearfishing (without tanks) and got buzzed by a 1m white-tip. Once he simply pointed his speargun at it, and it tooled off. The next time, he actually had to slam the butt of the gun on the shark's snout. The wee little thing kept circling him, though. He wasnt too thrilled, but we found it quite hilarious. He still gets friendly tips on how to save himself from marauding fusiliers.
On the other hand, Bob the Bullshark - all 4m of bad-tempered, territorial glory - has never displayed any signs of hostility other than 1 direct approach (with fins down, unfortuntately), followed by veering off at a respectable distance. Of course, with him, no one ever sticks around for a second warning - we simply swim away, and he leaves us alone.
I like sharks. Wouldnt want to see a big tiger, though - would much rather see a GW in the water than a tiger. Although recent reports I have read indicate that even tigers are not as aggressive as they were made out to be, I cannot help but note that virtually every instance I know of a diver being buzzed or bumped by a big shark has involved a tiger.
Anyone here dive off Rhode Island in 2001 and remember the supposed great white sighting off Providence? I have never seen such diligent buddy teams, and so many attentive people on deco stops, as I did back then!
Vandit