If you find yourself in a Samuel L. Jackson movie and not surrounded by any mutha f***in' snakes, good news! You're about to be eaten by a hyper-intelligent shark. These six tools will at least give you a fighting chance.
A shark's snout is packed with electroreceptor organs, called Ampullae of Lorenzini, which it uses to detect the electrical impulses of its prey's muscle contractions in murky waters. The six ferrite magnets embedded in this anklet each produce 720 gauss when submerged in sea water, which interferes with the shark's ampullary organ and makes you less of a target. $US25.
If you've ever been downwind from a ripened carcass, you've probably felt that deep, gut-checking revulsion at the smell of rotting flesh (don't worry, this is just a survival mechanism to keep you from being a dumb arse and trying to eat it). SCUBA/SPEAR produces the same reaction in sharks. This canister releases a cloud of the semiochemical repellent, shark necromone (literally "shark corpse"), into the water, shrouding you in the reek of decomposing shark. $US15.
The 720 gauss generated from the Magnetic Bead Anklet may repel smaller species like Lemons or Nurses but probably won't do much against, say, a 4m Tiger shark. The SharkShield Universal 7 uses two submerged electrodes to surround you with an 8m wide, ampullary-overloading electrical field. Any shark that invades your personal space will experience uncontrollable muscular spasms. $US590.
Sure at first glance, stabbing a shark seems about as effective as slapping or insulting its mother. But the WASP is a knife and a syringe, injecting a compressed gas (stored in the handle) at 800psi into whatever you're shivving. The gas freezes internal organs while inflating the offending predator and forcing it to the surface. $US500.
Speaking softly is more of a guideline than a rule when your big stick has a 12-gauge tip. Bangsticks pack an explosive charge (from .22 to .45 calibre) attached to a metre-long metal pole. Simply jam the business end of it against an overly-aggressive shark to show it who's boss. Or severely piss it off. Either way. $US100-$US125.
When all else fails, swaddle yourself in chain mail. Better yet, swaddle yourself in liquid crystal polymer fibre. The NemoII from Neptunic weaves this patented material over a standard wetsuit, providing divers a higher level of protection than suits constructed from steel mesh. However, much like ballistic armours, it will prevent a shark from sinking its teeth into you but can't protect against bones broken by a Great White's 1.8 tons of bite force.