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scubasteven45
09-08-2007, 02:04
My dive instructor many years back told me that when strobes are activated that the clicking draws attention to sharks. We had a night exercise and we were required to have them on so we could be seen. All I could think of though was click, click, click any one sense any sharks around, shark uh buddy shark? No just a dolphin dumbass! See he had us paranoid so does this hold true or is it something he came up with? Thanks

Damselfish
09-08-2007, 02:27
Strobes usually refers to camera strobes, which are only on for a split second but do have interesting sounds and electrical fields that can attract sharks. I don't think he was talking about regular dive lights. If he was, well that's a new one.

Aussie
09-08-2007, 04:54
I think scubasteve is refering to the strobes like the emergency strobes that flash every second.

Aussie

scubasteven45
09-08-2007, 13:27
The emergency strobes is what I was talking about. Kind you clip on your BC and can be seen from far distances.

somewhereinla
09-08-2007, 16:35
Sounds like one of those urban legends...

quarrydiver
09-08-2007, 16:45
never heard that one before.

Osprey
09-08-2007, 19:43
I haven't heard of this before, and a quick google search didn't find much either.. hmm

DivingsInMyBlood
09-08-2007, 19:59
all i can see now is a scooby doo episode with shaggy saying sh-sh-sh-sh-SHARK and scooby looking behind himself then only to freak out when face to face with a big smilling shark.

Osprey
09-08-2007, 21:43
Too bad it wasn't jabber jaw hahaha :)

diverdad
09-09-2007, 09:47
it sounds like a myth to me. but sharks are very curious creatures so they might come to investigate.just food for thought :smilie39:

Krakenn
09-10-2007, 00:25
We are required to use strobes in WA when diving at night.

Your post reminded me of a dive a few years back on the Star of Russia in Vanuatu. As I was putting it on the DM said to me it may be prudent that I dont put it on as the Sharks like them.

I put it back in my bag.

I have used them for years since and never had a shark incident but then again there isnt much coverage in the light at night is there. That bump in the back was ..... prolly my BCD and the tank moving around....... well I wasnt going to look back and to this day I never have...


Kraks

Desert_Diver
09-10-2007, 21:43
The tank light I use for night diving is a strobe. Never noticed any increased shark curiosity/activity while I was using it.

I did read one first person story by a National Geographic photographer who suffered a shark attack on him and his buddy. The photographer was very suspicious that the high whining noise that his photo flash strobe made while charging is what irritated the shark and provoked the attack. My memory is hazy but I think he was diving Chuuk (Truk).

Art

Harshal
09-11-2007, 16:05
Just a personal thought, if sharks were so good at receiving the clicks then shark researchers would not have to spend money on bait to attract sharks.
Also the other thought is I think they are more keen sense of smell then hearing. Please feel to correct me if I am wrong.
Maybe the strobes might be attracting shark as a visual cue and they come to check out what that flashing thing is.

Krakenn
09-18-2007, 23:56
I have had Tiger Sharks mouth my propellor of the boat and it is not an unheard of experience.

Sharks are attracted to electronic fields and it is said that they can feel your heart beat through the detectors in their snout. Its not unplausible that the strobe firing would cause interest.

I work on the basis if my times up my times up.

Kraks

sudnit5
09-19-2007, 01:36
I have never heard of that. Maybe you should email the Mythbusters.

DevilDiver
09-19-2007, 02:25
I have never heard of that. Maybe you should email the Mythbusters.
That is actually a great idea! :smiley32: I agree!

bversteegh
09-19-2007, 11:59
I work on the basis if my times up my times up.

Kraks

Exactly - could Jaws snatch any of us uw - sure. But taking a bath and driving a car are thousands of times more dangerous - and I don't plan to stop either of those 2 activities anytime soon:smiley20::smiley20:

Not that I would knowingly do anything to attract a shark unintentionally just because the odds are low he's hungry for a pudgy old man:smiley2:

Krakenn
09-20-2007, 06:14
Sigh, so many quick to comment.

I did a quick search for other examples

http://www.spec.com.au/?sp=r2004&id=4586

http://outdoors.webshots.com/photo/1192638098042428247QOzaSH

http://www.youtube.com/watch?v=UAPeMYwXLuc

http://www.marinebiodiversity.ca/shark/english/facts1.htm

There is actually more experiences than I thought.

Kraks :simpsons16:

DZorn00
09-20-2007, 06:53
Those are some nice links. Thanks for finding them.

greyzen
09-20-2007, 09:20
I could see how strobes could theoretically cause a short-circuit in the sharks brain to make it wanna check out what is happening (IE: bite it)

But short of covering yourself in dead fish and making sure to swim like a fish... I really think your odd's of getting bitten and/or attacked by a shark, unprovoked, is a lot lower than getting hit on the way to the dive site by someone on their cellphone.

diversteve
09-20-2007, 17:55
From "shark senses" on elasmodiver.com (http://www.elasmodiver.com/shark_senses.htm):

excerpted here:


Electroreception:
At some point during the evolution of elasmobranchs the lateral line pores around the snout became modified to respond to fluctuations of the electrical fields in the sharks habitat. These modified sensory organs are known as the ampullae of Lorenzini. They consist of relatively large bulbous pores filled with a gelatinous substance. Connected to the pores are cylindrical canals in which the gelatinous secretions are stored. At the base of each pore is a sensory nerve which transports the electrical signals (which are collected by sensory cells lining the pore) to the brain. Actively hunting sharks may have as many as 1500 ampullae around their snout and head whilst more sedate species may only have a few hundred. The ampullae also react to a lesser degree to temperature and pressure changes.

The ability of sharks and rays to detect weak electrical signals in their surroundings may be one of the greatest factors relating to their survival through the millennia. The organs are sensitive enough for hammerheads and some other sharks to detect the small electrical signals put out by their prey whilst it hides motionless below the sand. In fact the ampullae are so sensitive that they can pick up voltage fluctuations of just 10 millionths of a volt or the equivalent of the electrical gradient of a AA battery with wires put into the sea 1 mile apart. It has been suggested that the widened heads of the hammerhead family may be an adaptation designed to increase the triangulation capabilities of their electroreception.

Photographers (and I can testify to this) may have the unnerving experience of having a shark maul their underwater camera strobes which emit strong electrical fields. Sharks will also respond more aggressively to the erratic electrical signals emitted by a wounded animal. This may explain why shark attack victims are repeatedly bitten whilst rescuers swimming next to them often remain completely unscathed.

crpntr133
09-20-2007, 18:59
Exactly - could Jaws snatch any of us uw - sure. But taking a bath and driving a car are thousands of times more dangerous - and I don't plan to stop either of those 2 activities anytime soon:smiley20::smiley20:

Not that I would knowingly do anything to attract a shark unintentionally just because the odds are low he's hungry for a pudgy old man:smiley2:

And I thought that driving while talking on the phone was difficult. Never heard of bathing and driving.

bversteegh
09-21-2007, 01:49
Exactly - could Jaws snatch any of us uw - sure. But taking a bath and driving a car are thousands of times more dangerous - and I don't plan to stop either of those 2 activities anytime soon:smiley20::smiley20:

Not that I would knowingly do anything to attract a shark unintentionally just because the odds are low he's hungry for a pudgy old man:smiley2:

And I thought that driving while talking on the phone was difficult. Never heard of bathing and driving.


Guess I should have used two sentences. If you look at accident statistics, getting hurt/killed in a car wreck is number one. Inside your house, slipping and falling in a bath tub is one of the biggest source of accidents - and several fatalities a year.

WaScubaDude
09-21-2007, 02:40
so clip your strobing signal light to the french guy.

diverdad
09-21-2007, 18:11
Some people just fear the unknown it is natural. But it should not stop you from enjoying life underwater.

Krakenn
10-02-2007, 07:55
Well researched DiverSteve.

Kraks