I think DougB got it right. I got certified as a NAUI Open Water 1 while living in Washington(Puget Sound). I learned about bang sticks, but the instructors who taught our group (former Navy divers, no SEALS) said that most sharkes don't bother you. Further, they said that if a shark does approach you they do it slowly and it is easy to punch them on the snout. They thought bangsticks were unnecessary and dangerous, and anything you would need a bangstick for is a drop in the bucket compared to ALL THE OTHER potential problems that would most likely happen to you. If you run into a Great While or a Tiger Shark, well then yer just gonna get munched regardless of a .44 mag bangstick
Mike