Device to shock sharks - will pod keep going?

It was the scariest situation," says National Geographic filmmaker Nick Caloyianis, recalling his brush with a phalanx of sharks off the coast of South Africa.

"There was such a frenzy that the sharks tended to bite just about anything.... We saw bite marks on dolphins, and it was the kind of situation where divers shouldn't even be in the water."

For Mr. Caloyianis, it was the most rigorous test of the Shark Pod, a commercially available electrical shark-repellent device for scuba divers. Some are hailing it as a breakthrough technology, while others are questioning its true effectiveness under certain circumstances.

"I had two people in there with me. We all stuck together like glue," he recalls. "I was wearing the Shark Pod ... and the sharks would be repelled by the [electrical] field that was produced by the Shark Pod. In South Africa, I wouldn't go in the water with those sharks ... without this thing."

The pod itself was developed and produced in South Africa by the Natal Sharks Board, a 35-year-old quasi-governmental organization charged with protecting the beaches of South Africa's KwaZulu-Natal Province from the ocean predators.

The Shark Pod consists of an electrical pack with two electrodes, one of which is connected to the diver's air tank, while the other fits onto the diver's fin. The device emits a low-power electrical field that confuses a shark's internal sensory systems.

Well, theoretically at least.

Even the Shark Pod's manufacturers admit the pod doesn't work in every circumstance. Nor on every shark. Caloyianis attests to this after he tested the pod in the Bahamas.

"A lot of people think sharks are stupid and can't learn anything, but they can. It was obvious with our experiments in just one week that the sharks ... seemed to have the tools developed in their front end to ... find a hole or a path of least resistance."

Most agree that the Shark Pod's limitations have been in situations where divers have stimulated a shark feeding frenzy with bait, rather than the rare one-off encounter that the pod is designed for.

But what use is the device against the big boys? "Surprisingly, most of our test data is on great whites," says Theo Meyer, one of the shark pod's developers, noting its success against the feared fish.

The Natal Sharks Board is hopeful that the Shark Pod will have other spin-off applications beyond its use to divers and spearfishermen. Ideally, they would love to be able to replace the nets off South Africa's beaches with some form of electrical field, which would kill fewer sharks and other sea life.

There has also been talk of miniaturizing the pod so that it could be attached to surfboards, sailboards, life-jackets, or even bathing suits.

"The problem is that we don't have the money to invest in the technology," says Geremy Cliff, the Natal Sharks Board's attack expert. "Maybe we'll get some guy who has a couple of spare millions to throw at the project and just take it that step further."

(c) Copyright 1999. The Christian Science Publishing Society