Deterrent

Though there are just six fatal shark attacks each year globally, going for a swim off the back of a boat is not a pastime undertaken lightly. Now there's a scientifically-proven device which deters sharks and enables far safer ocean swimming. Is keeping the kids safe worth US$3,000?

​Since at least 2004, surfers, swimmers and scuba divers have been able to buy an electronic shark-deterrent device known as the Shark Shield. Its patented technology is now being offered in a handheld speargun-like gadget, called the eSpear.

​While we've seen a number of devices that use ultrasound to ward off mosquitos, many people maintain that such deterrent systems just don't work. The Nopixgo Mosquito Bite Protection Wristband takes a different approach, emitting electromagnetic waves instead.

Hamburg's St. Pauli is one of the world's most famous red light districts, attracting around 20 million visitors a year, and a good number of those visitors urinate in public places. Now, in a fit of poetic justice, the walls of St. Pauli are being upgraded so they retaliate on micturators in kind.

WatchStander is a radar system that's designed to pick out small boats, such as the low-slung skiffs often used by pirates. It then tracks the vessels, and deters them if it looks like they're going to attack.

Researchers have identified the gene that causes barnacles to react to medetomidine, opening up the possibility of an antifouling paint that is gentle to both barnacles and the environment.

Drink No More is a deterrent that lets you know when your pet is approaching the toilet and, hopefully, scares it off with an alarm and flashing light.