It's not known how long Tigers can go without eating, but they soon seem to feed whenever a food source is present. It's also not known why Tigers sometimes attack humans. Divers who may encounter sharks often carry a shark billy or a bang stick. A billy is a club used to fend off a shark by hitting it on the snout. A bang stick is a rod with an explosive charge at the tip, used to kill an aggressive shark.
Bang sticks are effective, but very dangerous.
In addition, the resulting blood may attract other sharks. Shark attacks in Hawaiian waters are very rare , occuring on the average at a rate of about two or three per year. Surfers and spearfishers appear to be most at risk. People who enter the water need to recognize that there are hidden dangers, and sharks are just one of them . By learning more about sharks, and using common sense, the risk of injury can be greatly reduced.