Sharkshield article in Chronicle

SFGate.com
A new way to prevent shark attack

Tom Stienstra

Sunday, July 27, 2008
Shark Shield is an electronic shark deterrent that can be...

(07-26) 17:56 PDT --

When the shark appeared, the husband and wife in their double kayak had paddled for only 10 minutes, reaching just past the mouth of the harbor.

"It surfaced next to us like a submarine," said Jon Schwartz. "It was like 9, 10 feet long, directly perpendicular to us, about 12 feet away, a tiger shark, about 200 pounds. It was staring at us, right next to us. Our worst fear was right in front of us."

The shark then looped around and charged right at them.

Schwartz's wife, Veronica, screamed at her husband. "Put that thing in the water"" she recounted shouting. "Turn that thing on!"

In this case, "that thing," was a Shark Shield, a new device for kayakers, surfers and divers that emits an electronic field designed to repel sharks.

The shark was close enough, Veronica said, "to see its teeth."

"I could see its whole head," Veronica said. "Its mouth was open. I was so scared. I will never forget it opening its mouth as it came for us."

In the chaos of the moment, Schwartz said he remembers flipping a switch to activate the Shark Shield. They watched as the shark suddenly veered off just a few feet from them.

"It was as if the shark hit a force field," Schwartz said.

The pair said they went crazy with relief, shouting and hooting. "It was unbelievable," Veronica said.

This episode took place in Kona, Hawaii, where I tracked down Jon and Veronica Schwartz this past week, and where numerous tiger shark attacks have occurred. The idea of a Shark Shield could have a profound effect on recreation on the Bay Area and California coasts as the peak season arrives for great white sharks. It coincides with the annual Shark Week on the Discovery Channel.

The credibility of the account is amplified because Jon Schwartz, 39, is better known as "Bluewater Jon," one of the world's most renowned kayak fishermen. Earlier this year, he caught and released eight marlin ranging 130 to 150 pounds, all recorded on film, in little over a week fishing in his little kayak out of Cabo San Lucas. Late this past week, out of Kona, he landed a 100-pound sandbar shark from his kayak, and then said with a laugh, "We were hoping for something much bigger." He lives in Carlsbad near San Diego, "about 10 minutes from where a swimmer got munched by a great white this year."

After the episode with the tiger shark, he says he will never kayak again in the ocean without the Shark Shield mounted and activated. "I know it sounds like an advertisement," Schwartz said, "but I've seen it work." As a parent with three children, he added, "I think about my family a lot."

Shark Shield was developed in the past five years in Australia, home for many of the world's largest great white sharks. It can be mounted on the back of a surfboard or a kayak, and a lightweight neoprene model that can be strapped to the calf of a diver. They cost roughly from $680 to $800.

They consist of a rechargeable battery in a waterproof pack, transmitter and rubber-coated antenna. Batteries are available that last four and seven hours.

According to Paul Lunn of Shark Shield, the antenna produces an electronic field that extends about 10 feet in diameter, which in turn, wards off sharks.

The principle behind the device is not new. It's been long known that electronic fields can attract or repel fish. Even in the 1960s, commercial fishermen were aware that their wire downrigger lines could react in a synergism with their boat's hull to create electronic fields. That is why some boats catch fish and others do not, according to Dick Pool, the retired Bay Area engineer who studied the concept for 20 years.

That is why Pool developed the "Black Box," which is mounted on boats with downriggers to create electronic fields that simulate schools of baitfish, and in turn, attract fish to the boat. Pool said that his studies show that the contrary is also true, that the wrong electronic field will repel fish, not attract them.

Sharks have electronic receptors in their snouts that they use for navigation and to find food, so the same inspiration that Pool used to develop the Black Box is the foundation of the Shark Shield.

Not all the press regarding Shark Shield has been positive, due to two outrageous incidents, one that occurred in 2005 off of South Australia and another off South Africa.

In the first, a diver with a university research dive team that had been provided with two Shark Shields was attacked and killed by a great white shark. During the inquest, it was determined that the divers did not wear the devices.

In the other, a story out of South Africa that circulated on the internet said a great white shark ate some bait that was on a line from a surfboard equipped with a test model. Lunn said that episode was the case of a test model with an undersized antenna, and in the field, 13,000 units have been sold without a failure.

Some shark experts have also theorized that if a shark were hungry enough, nothing would slow it down, even if the Shark Shield is effective deterrent in most episodes.

After seeing a tiger shark turned aside, Veronica Schwartz has no such reservations.

"We have three girls," she said. "If something had happened, what would have happened to them?" Then she added: "Every time I go in the ocean, I definitely bring the Shark Shield. Definitely. It's the first thing I remind Jon. Make sure you take that thing. Make sure it's on."

"The Great Outdoors With Tom Stienstra" airs Sundays at 10 a.m. on KMAX-31 Sacramento.
More info

Shark Shield: sharkshield.co.za

Bluewater Jon: bluewaterjon.com

Shark Week: dsc.discovery.com

E-mail Tom Stienstra at tstienstra@sfchronicle.com.

yakuza, great article...hopr you dont mind if i put a link to it on the official GWS thread

yakuza, great article...hopr you dont mind if i put a link to it on the official GWS thread

DOH!  forgot about that thread...that's where it should be.

I saw somewhere that GWs are now hitting trolled seal decoys after dark. They are suspected of using light pollution from harbors and cities.

If I kayak in tiger waters, I will consider purchase of the shield but for norcal GWs, best to paddle with a hobie 

-Brian G

Still want to see more studies with great whites and not Tigers.....AND I'd like to see the shark shield stop a full bore attack from a GW...you know, the full speed ambush kill from below

AND I'd like to see the shark shield stop a full bore attack from a GW...you know, the full speed ambush kill from below 

Not going to happen, In that situation,....

Best just to put your head between your legs and Kiss Your arse Goodbye....

AND I'd like to see the shark shield stop a full bore attack from a GW...you know, the full speed ambush kill from below 

Not going to happen, In that situation,....

Best just to put your head between your legs and Kiss Your arse Goodbye....

I understand the sentiment, but my experience is it ain't over till its over. Bite, punch and kick. remember you have a paddle in your hand. use it. Go for the eyes, gills , organs or nose.
Mooch, Ive seen both whitey and Mr T in action. IMO if it is effective on an aggressive large Tiger it should be ample to turn a white. IMO Mr T is a more aggressive customer.
There is alot of talk about the ballistic vertical attack method employed by whitey. IMO what has happend is they have found a fishing technique that triggers this type of attack.Troll speed being the key(like otherwise uncooperative tuna which "light up" as soon as you get on the troll). notice what happens after they have brought the fish to the surface and kick the boat into neutral. very often the fish "rolls" on the decoy. my attack was not a ballistic vertical attack, nor was my friend Sergio's (was Dan's, honestly, i don't know). None of the few human attacks caught on camera that i have seen were. they were all shallow angle of approach attacks. the types of attack that leave marks under the board and on the victims back. These attacks seem more tentative and exploratory. As if you look interesting but their not sure. they may be unsure why you didn't take off like a bat outta hell after their first pass. I believe the ballistic attack is triggered by the HIGH SPEED TROLLING of a realistic decoy.
The shield may or may not prevent a ballistic attack, but once the fish is in the field of protection field it will switch from offense to "get the hell outta here". you may get bumped(although i have confidence it'll turn), but should avoid death or injury.
i know i sound like a SS rep. i apologize. i just want us all to be safe as possible out there!
Danglin, i believe if you have your shield with you up at elk and allow people to turn it on and off  and mess around with it in the salt we will have a few converts

"It was like 9, 10 feet long, directly perpendicular to us, about 12 feet away, a tiger shark, about 200 pounds.

Am I way off or does it seem like something is way off with these numbers.  Maybe just a typographical error or possible the world's most emaciated shark.

Very interesting article, thanks Yakuza.

Michael

My posting of that article should not be construed as endorsing or dismissing the product.  Though i have no plans on getting one, I won't knock people for trying to fill the need. .

I'd like to see some good studies on this device.  Be great if efficacy were proved.