agree with sven regarding the powerheads. in my opinion, if you have the time to stick it on your speartip, the shark isnt really interested in you anyway. especially the whites. i watched that documentory on air jaws in false bay, and there they say the sharks use the murk layer to stalk their prey, the seals, so if he wants you, you're not going to see him comming. also if you do have problems with a solitary shark like a great white, then i'm pretty sure that, if it comes to that, putting your spear into its head will be enough to put it off. i've heard of storys like that, but i've never heard of anyone putting a powerhead into a white. the only time i would consider using a powerhead is if you get mobbed by a pack of smaller sharks. the blacktips over hear can get very cheeky, or els those oceanic whitetips
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my question with viz comes down to the following theroy.
zero viz - shark bumps/bites you to see what you are
bad viz - shark comes very close before you see it
good viz- you have a better chance of seeeing the curious sharks
excellent viz - you dont ever get to dive, or you live on a tropical island, and i dont want to hear about it.
this applies to when the sharks are in curious mode. if they are pissed off, then the better viz gives you a chance to point your gun in the right direction.
another problem with bad viz is what you do with your fish once its been shot. i've been taxed before without even noticing, and thats with a 20m floatline
