and that's exactly what a tourist is capturing on his video camera. >> what i was filming was two surfers paddling for the same wave. >> but in just seconds, the tourist would record something rarely seen on video -- two great whites in a vicious attack on the young surfer. it all happens in a flash. the first shark rips a massive chunk out of shannon's board and sends him plummeting into the water. the great white gets a piece of his hand as the shark's dorsal fin flops in the surf. the second shark, seen here beneath the waves, swims alongside, perhaps looking for leftovers. shannon's friends see the horror from shore and scramble to save him. he's severely wounded. blood spills from his freshly mangled hand. but within a minute, shannon is safe on the beach.