KZN Sharks Board - Electrical shark repellent

Electrical Shark Repellent
For over a decade the KZN Sharks Board experimented in the use of electrical fields to repel sharks. In 1996 this culminated in the development and sale of a successful electrical shark repellent, the SharkPOD (Protective Oceanic Device). Distribution of the SharkPOD ended in 2001.
The SharkPOD Diver Unit was specifically designed for use by SCUBA divers. Most of the sales were to commercial divers, as recreational divers want to see sharks rather than repel them. The concept was later modified for use by commercial, surface-supply divers, who obtain their air from the surface via an airline.

The SharkPOD Diver Unit consisted of three components linked by cables.
The main body of the Diver Unit, housing a small rechargeable 12 V battery pack and one stainless steel electrode, was strapped to the dive cylinder. The foot electrode was attached to one of the diver's fins. The activating switch, which also housed the low battery warning light, was brought over the shoulder to make it easily accessible. Separated by at least 1.5m, the two electrodes created an electrical field around the diver, which was designed to repel sharks approaching from any direction. This field appeared to affect the shark’s sensory and neuromuscular systems and discouraged the shark from remaining in the immediate vicinity.

Simulated electrical field created by the SharkPOD Diver Unit

The SharkPOD proved effective in scientifically controlled field tests, repelling sharks that came "too close for comfort" (i.e. 1m from the SharkPOD). Most of these tests were conducted on white sharks Carcharodon carcharias on South Africa’s southwest coastline, which is internationally renowned as the best region in which to encounter this species. Tests against the other two species of dangerous sharks which divers are likely to encounter in nearshore waters, namely the tiger Galeocerdo cuvieri and the bull (Zambezi) shark Carcharhinus leucas, were limited but with good results. The effectiveness of the device varied according to species, and some harmless sharks, such as the nurse shark Ginglymostoma cirratum, showed little reaction to the electrical field.
The SharkPOD Diver Unit was designed to be activated immediately on entering the water and switched off again only when leaving the water. The device was not intended to be switched on and off during a dive as a startle device - it functioned by keeping sharks at bay. When used correctly, the electrical field was not strong enough to cause undue discomfort to humans.

The Future
The KZNSB has ceded the patent to POD Holdings Ltd, in which company the KZNSB is a shareholder. POD has in turn licensed an Australian company, Seachange Technologies, to develop a new product for divers as well other applications of the intellectual product. The KZNSB will test and approve prototypes of all new applications.
http://www.sharkshield.com

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