There are sharks in the water

One of the benefits of my day job is that I get exposed to any number of gadgets and electronics through customer interaction and trade journals. Last Fall, I came across a device (essentially a big magnet you strap onto your wrist or ankle) designed to repeal certain species of sharks, especially in shallow water. As I have no intention of going deep-sea cage diving with Great Whites (why does anyone do this?), I placed the device on my Christmas wish list as moreof a joke than anything else...