The Arizona Republic

Mark Thurlow, one of two shark masters, did a 360-degree turn in the water to check for sharks swimming between the dive platform and the shark cage. With a circle of fingers, each diver signaled OK to the chain-suited dive master and took a giant stride into the 3,500-foot frigid 60-degree water.

Mashing tuna in a plastic grate, the chum (bait) line drifted away from the boat, attracting sharks within 17 minutes. When sharks began to circle the boat, two steel cages were dropped into the water.When the moment of truth arrived, each of the divers was wearing a full wetsuit with hood, plus an additional 25 pounds on their weight belts. The extra weight created negative buoyancy, making it easier to stand in the cage. Other dive gauges were removed to prevent the possibility of tangling during the entry or exit from the shark cage.

During the trip to the dive site, 20 miles west of San Diego, 12 divers had made a check-out dive to practice entering and exiting the cage. Diving with sharks is only for the experienced dive, and while experienced, none of them had experienced caged shark diving. The majority of divers had previously dived with reef and nurse sharks but not with baited pelagics in open water.Each of the divers shared an “adrenaline junkie” persona that brought them together on this adventure. They had signed a witnessed liability release declaring that “scuba diving is dangerous, the open sea is a dangerous environment. The primary intent of the expedition is to attract dangerous and unpredictable sharks by baiting them. There may also be other animals and water conditions that are dangerous.”

All had signed a few releases over the years, but this one certainly got the groups attention.

Explaining the attraction of shark diving to non-divers is difficult. Some thought the San Diego diving trip was a good opportunity to become aware of comfort levels of diving with sharks with the added safety of the cage. One diver was planning a trip to the Cocos Islands, south of Costa Rica, where she would spend a week diving with hammerhead sharks in open water.

She would later discover that she felt more comfortable in open water with elusive hammerheads. There was the freedom of swimming instead of the confinement of a cage. Her stomach grew uneasy from swaying in the current while motionless in the frigid water with baited sharks in a feeding frenzy surrounding the cage.Through a camera lens, the divers observed the two shark masters, wearing 20-pound stainless steel neptunic shark suits, feed the sharks. Putting their hands and arms in the sharks mouth, they said that they felt only light pressure from the gnawing teeth. The sharks razor-sharp teeth occasionally caught on their steel-mesh-covered hands. The shark master would push the nose of the shark to release his hand from the sharks mouth.

To the divers, exiting the cage was the most frightening part of the experience. The sharks had been feeding for more than two hours. As the divers ascended to the boat, there was no view of the sharks. The shark master quickly guided the group back to the dive ladder of the boat.

Scuba diving with sharks is not for everyone. Most divers have more than 100 dives under their weight belt before experiencing their first shark sighting. A diver hoping to see sharks scans the blue water away from the reef wall, searching for a glimpse of the “big stuff,” open-water pelagics including sharks, whales and mantas.