GANSBAAI, South Africa — Submerged chest-deep in a cage, seven tourists clad in wet suits helplessly bobbed in the Atlantic Ocean's relentless swells. Many had traveled halfway around the world to South Africa, where they hoped to catch a glimpse of the ocean's most fierce and feared creature: the great white shark.
The cage was the only thing between the predator and them. Half-inch bars didn't seem thick enough or close enough together; a man's leg could slip through easily. And wet suits didn't keep the divers' lips from turning sickly shades of purple in the 50-degree water.
But soon enough, they forgot about the cage and the cold. A 15-foot great white appeared 10 feet away in the murky water. A crew member tossed a bait line to coax it in. The shark lurched toward the cage as it pursued the bait, its jaws wide open, revealing rows upon rows of teeth.
Then, as quickly as it appeared, the shark was gone. The tourists resurfaced, amazed by what they'd just seen.
These thrilling excursions are at the heart of a controversy flaring along the South African coast that pits the decade-old cage-diving industry against surfers and environmental activists. The critics charge that one of South Africa's most popular tourist attractions is contributing to an increase in shark attacks and fatalities because the bait tour operators use — fish oils, blood, even tuna heads — is conditioning the great whites to associate humans with easy meals.
"I think cage diving is great because it brings tourists," said surfer Stuart Miller, 15, of Cape Town. "So long as no one dies."
Though there are only about 3,500 great whites in the world, shark attacks on people have been on the rise in South African waters. There are many possible reasons: more people spending more time in the water, more tourists visiting post-apartheid South Africa, and the addition of great white sharks to the country's protected species list.
While evidence linking the cage-diving industry to shark attacks is inconclusive, South Africa saw a drastic increase in attacks from 2000 to 2004, the first years that the excursions were allowed.
For many surfers, the cage-diving industry is the factor that can be controlled most easily. But some anticage-diving activists claim to be afraid to speak out openly because of the industry's financial clout.
From 2000 to 2008, there were 27 shark attacks in South Africa, two of which were fatal, according to the International Shark Attack File, maintained by the American Elasmobranch Society and the Florida Museum of Natural History. Annually, five to 15 people die worldwide. But in 2009 and 2010, there were 14 attacks in South Africa. Six people died.
Tour operators describe cage diving as a conservation experience: Tourists pay to see the sharks while operators use the opportunity to observe and research great whites.