Note to self: Dont take tuna heads when diving next.

First comment: "While I've always been dubious of the shark shields, I question how much a surfer in the water resembles a hunk of bleeding tuna bait... I mean, I would endure a painfully shrieking siren for a few seconds to retrieve $1000, but I wouldn't endure it for a suspicious looking bag that may or may not contain anything at all"

I dont think shark shield say they guarantee it will work, or all of the time, but neither do seatbelts. I figure if a shark wants to eat you (like food in the video), he'll ignore the tingling, but if its curious and wants to nudge up against you with some test bites, it might deter them more often than if you didnt have one. Aint no guarantees, but i'll take reduced likelihood over nothing (and other videos do show it does deter them at least some of the time, as do the people who've used them up north to stop being bitten off while fishing).

One of the comments on swellnet:

1.The tests were conducted in an extreme, unrealistic environment where there's shark cage diving and the water was chummed. It has been demonstrated that chumming changes shark behavior.

2. For the tuna tests the unit was placed within 2-3m, and when SS was ON the length of time doubled from 122 seconds to 244 seconds for the shark to take the bait.

3. Seal decoys were towed behind a boat at 8-10km per hour with a SS ON and suspended at 2 meters and there were NO surface breaches.

4. When the same seal decoys were towed with the SS OFF there were 16 surface breaches. The purpose of Shark Shield is to safely get to shore or a boat in the event of a shark sighting, not to swim with sharks.

Was on the rescue boat doing the body recovery from the boat vs barge collision off Carnarvon a few years back, the chopper had warned the police divers that there was 3 sharks over the wreck, 1 x 10 footer and 2 x 8 footers before they entered the water.

The crash had happened some 30 hours before and the three bodies were inside the cabin of the boat in 30 foot of water, according to the divers during the debriefing when it was all over, the sharks came to within 20 feet of them and took off once they felt the electrical current then circled at what was a safe distance for them not to get shocked again but didn't leave the scene because of all the leaking body fluids.

The divers need medals and huge wages for what they do and I'm sure they would have had second thought about hopping in the water knowing what awaited them without a shark shield.

 of some guys up north doing some test on two differnt brands they had a bait (1/2 a coral trout ) tyed to a shark sheild on a pole with a gopro camera on there aswell ,the black tip sharks seemed to be a little aprehensive about having a nibble but they still had a bite then took of in a hurry ,which was a better result than the other brand that didnt seem to phase the hammer head that came in and chewed on the bait for a while  

I have two shark sheilds one for jesse and one for myself , Diving the Abrolhos we have seen two sharks and both have not shown any intrest in us  just keeped swimming through .The sharksheilds did not make the sharks come in for a closer look.A they didn't get close enough to see if the sheilds had ant effect on them .as for the shock from them harden up .I grab mine through out the dive to make shore its working ,not to bad on the head or over the shoulder tings a bit.

Seems like that article either has a bit of an agenda or the person writing it only watched the video instead of reading the actual scientific report. Have a read of this article it does a much better job of breaking down and explaining the test results:

http://www.abc.net.au/local/stories/2012/06/20/3529306.ht

I've personally seen the shield work on a big tiger that got really aggressive with me while spearfishing a couple of years ago and the test results are about what I expected. It's a long way from full proof and it's not gonna stop a great white that decides you're food but it has an effect and if that means a great white hesitates and comes for a closer look instead of ambushing me from a distance or decides to give me twice as long to get out of the water before having a bite I think that's a good investment.

 of the older units, purchase in 07, wont dive with out it!!.

 Even with the shocks running through my fillings giving me the occasional head sting!!

Based on what a lot of spear fishers in north queensland said about them. They tie them to their floats and say thet work keeping the tigers and bull sharks from taking their catch. Good enough for me. While they probably dont work when a big white is in attack mode they are designed to stop them when investigating. If you get a visit from a big white i bet you wished you had one on...

 When's the last time a scuba diver has been attacked by a shark in WA/Australia?

I definitley havent heard of an recent attacks. I wore a shark shield for the first time ever when scuba diving the other day due to uni policies, and I can say that given the cholice i wouldn't wear one on scuba. The zapping and entanglment was quite annoying, and i really dont think a shark is going to attack a scuba diver anyway (well it's unlikley).

Spearfishing on the other hand I would consider it. Spearing is the only time i feel vulnerable to sharks, mainly because you are basically basically a sitting duck on the surface half the time, and you are pretty much berlying the sharks up.