Shark repellent - Page 1
Forum section: electronics / projects

author: Wytnucls
author_rank: Super Contributor
timestamp: November 26, 2013, 12:48:52 pm
content: Another surfer was killed by a white shark in Western Australia, while I was in Perth, last week. Thinking about a way to repel sharks from surfboards, I found out that some studies were done with underwater acoustic and magnetic devices, which were partly successful. I was wondering how difficult it would be, with today's powerful batteries, to turn a surfboard into a high tech shark repelling machine, while keeping the weight manageable. They are some problems, as a magnetic field loses power rapidly with distance and a shark uses all its senses, including sight, to zero in on its prey. Any bright ideas?http://www.foxnews.com/us/2013/11/23/surfer-killed-in-shark-attack-off-west-australia/

author: fluxcapacitor
author_rank: Frequent Contributor
timestamp: November 26, 2013, 01:04:43 pm
content: A quick google search ,i found something called shark shield.It can be attatched to surfboards :http://www.sharkshield.com/There seems to be lots of other products that claim to do the same thing.I`d hate to be one of the testers

author: Wytnucls
author_rank: Super Contributor
timestamp: November 26, 2013, 01:25:03 pm
content: They make some bold claims for that Sharkshield device, but it seems that potential customers don't really trust its effectiveness, or perhaps it is to expensive for casual surfers. Underwater testing with lethal sharks is difficult, to say the least, but crucial to validate the effectiveness of new gizmos.

author: BravoV
author_rank: Super Contributor
timestamp: November 26, 2013, 01:30:04 pm
content: Wytnucls, since you originated from South Africa, probably that is one of the best field for testing is by dragging a seal shaped dummy attached with that repellent to see if the "flying shark" will jump on it ? Your thread reminds me one of the Mythbusters series.

author: kayvee
author_rank: Regular Contributor
timestamp: November 26, 2013, 01:38:48 pm
content: I knew an ex-colleague down here in Durban who did a lot of research in that area and has a patent.http://www.freepatentsonline.com/8456310.htmlNo idea what came of it commercially, lost touch many years ago.

author: JohnnyGringo
author_rank: Regular Contributor
timestamp: November 26, 2013, 02:23:37 pm
content: Quote from: Wytnucls on November 26, 2013, 01:25:03 pmI'd think it would be fairly easy to test. Throw some chum (fish-bait, not your BFF) in the water followed by one of these devices and see if the sharks run away.

author: SeanB
author_rank: Super Contributor
timestamp: November 26, 2013, 06:35:25 pm
content: Nothing wrong with the gents in grey suits, I used to quite enjoy watching them out at the backline swimming nicely inside the shark nets. In sardine season of course you definitely do not want to fall off into the water.You might want to try using repellent capsules, they are supposed to work. The electric field generator idea does seem to be a good workable idea, I will skipper the boat and tow you...... Might toss a rod or two over the side with chokka and look for some rock cod as well, though if the gents are around I generally only get either a head or half a hook back. Pulled up a 4m Zambezi one day, which realised it was next to the boat and decided to leave by biting through the steel trace.

author: Marco
author_rank: Super Contributor
timestamp: November 26, 2013, 07:40:18 pm
content: Here's a recent study, seems it's not 100% effective.http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3642219/?tool=pmcentrezMaybe a more active approach would be more effective? Use active sonar to detect incoming sharks and then just give them a huge bolt of focused ultrasound with a phased array.

author: Wytnucls
author_rank: Super Contributor
timestamp: November 27, 2013, 02:11:24 am
content: I like your idea Marco, sounds like sub warfare.I'm surprised no one has tried to turn their surfboard into Starship Galactica yet, complete with strobe, underwater 'fisheye' lens camera with early warning 'sharkface' recognition, microwave magnetron, Kevlar suit, reactive armor and possibly a whale cannon, to impress the girls on the beach.

author: ablacon64
author_rank: Frequent Contributor
timestamp: November 27, 2013, 02:25:27 am
content: Sounds like some Maxsteel suit!

author: Stonent
author_rank: Super Contributor
timestamp: November 27, 2013, 04:19:50 am
content: I was thinking something along the lines of loud angry dolphin sounds to keep sharks away.

author: bench_knob
author_rank: Regular Contributor
timestamp: November 27, 2013, 05:04:26 am
content: Quote from: Wytnucls on November 26, 2013, 12:48:52 pmFirst, its a bummer about the surfer. Its just another removed anecdote for some of us, but somebody out there is weeping....and I feel for them. Plus, I experienced a shark that jumped into a cabin-cruiser with us (Biloxi Mississippi) durring a fishing trip out to the islands. It was exciting.Here in LA Ca USa, a few years ago I knew a gal who worked with dolphins/porpoise at the San Diego SeaWorld park. She was a linguist, Ph.D. type who had a contract with the US DoD through UCLA.edu. She attended one of my ET-Contact parties in my home and during conversation the subject of sharks was braced. She said that they used diluted shark's blood as a wide-area deterrent for sharks. It seems that when sharks 'smell' their own blood, they all immediately head out to open waters, and then dive deep, down below killer-whale diving depth. Aside from Humans, sharks only threat is killer-whales, which attack them, bite them in the liver area, but not to kill them bleed out, which signals to the sharks that they are around. Apparently they do this as sharks scare away penguins, seals, sea-otters and sea-lions...killer-whale dinner.And then recently, I watched a PBS documentary where California scientists also made similar discovery, using shark's blood, only they had tagged a number of sharks, which all disappeared from the area, resurfacing in Hawaii after pouring a small amount of shark's blood into the surf around Santa Monica.And the neat thing about it, it doesn't harm the other wild-life in the surrounding area, as apparently high-power accoustics apparently does.bench knob

author: Wytnucls
author_rank: Super Contributor
timestamp: November 27, 2013, 05:23:39 am
content: Apparently, WW2 researchers noticed that shark blood could be used as a repellent. Essential compounds were extracted, packaged and issued to US Navy airmen, likely to end up in the drink, during that conflict. The problem is that it doesn't work with all types of dangerous sharks. Some dye was also mixed in, for good measure, to interfere with shark vision.

author: Maxlor
author_rank: Frequent Contributor
timestamp: November 27, 2013, 07:35:52 am
content: There might be a non-electronic approach to this:http://www.fastcodesign.com/1673207/can-this-surf-gear-prevent-shark-attacks

author: Stonent
author_rank: Super Contributor
timestamp: November 27, 2013, 12:18:17 pm
content: Just bring a lawyer. Sharks won't eat them out of professional courtesy.

author: Stonent
author_rank: Super Contributor
timestamp: November 27, 2013, 07:34:44 pm
content: I'm a shaaaaark! **** my ****! I'm a shaaark!

author: vk6zgo
author_rank: Super Contributor
timestamp: November 28, 2013, 04:47:46 am
content: Quote from: bench_knob on November 27, 2013, 05:04:26 amSharks quite happily eat other sharks,even of the same species.