Does crunching plastic bottle attract sharks?

[ccredifo]

I was diving in the Cayman Islands years ago and our Divemaster brought a plastic bottle on our dive. As we got to 80 feet the bottle was partially collapsed. He was moving it back and forth between his hands which produced a loud, crunching noise. After a few minutes a shark came swimming by us.

We thought it was a joke but the DM said it works everytime. I was channel flipping last night and saw a brief discussion about this very topic. I didn't get to see whether it produced the same results.

I'm going to Maui in February and going to give it a shot. Has anyone else tried this trick?

[UnderSeaBumbleBee]

interesting . . .

[porbeagle]

Hi CC.....
Most any sound will attract sharks,as they are very curious.
Trick is to keep them in the area without feeding them or
chumming. I find that my remaining horizontal in the water column
helps them to be more relaxed, a stick banged on your tank works as well as
a plastic bottle.Every shark within every species will act differently.
You might want to be aware of threat posture positions of the species you are
most likely to encounter in the area you shall be diving. But above all, just relax
and enjoy them. They know when you are relaxed and are as curious as you are.
PORBEAGLE

[Parso]

I tried this at a local dive site here in Sydney, where I new there were young Dusky Whalers present, and believe me, the trick worked quite well. The sharks came a lot closer than normal and they seemed to find me rather quickly.
I must tell you though, I tried the same thing the week later and did not see one shark. Maybe the first time was a coincidence or maybe there were no sharks around on the second attempt.

[spt29970]

Last week I was at Guadalupe Island and now that the rules for interacting with the Great White Sharks have changed (no chumming or wrangling), people are very interested in whether noise will attract the sharks. Several people banged on the cages to get their attention. My observation is mixed, sometimes it seemed that they reacted the noise, other times they seemed to ignore it. I suspect that it would be hard to prove either way. I have some images at: Guadalupe Shark Diving - a set on Flickr (http://www.flickr.com/photos/drsteve/sets/72157607869293974/)

[c. carcharias]

Not so much the noise, its the vibration against the latteral line. Light, irratic vibrations will simulate an injured fish. Too strong and will be uncomfortable and they will leave. I have seen a few things work as long as a shark is in the area.
water bottle filled halfway with water.
two coconuts on a large hoop banging from the surface
some fishing flashers make a baby rattle too attract fish

[c. carcharias]

Its important that a shark is in immediate area, chum works alot better for attracting long distant sharks

[archman]

They'll use hearing for picking up bottle crunching. The lateral line system has a pretty short range.

[wedivebc]

I have seen it work in Thailand. Very effective.

[c-dog]

Yes, I think this techique works very well but it depends on the species. Low frequency vibrations can travel great distances underwater. some curious sharks, like blue sharks, are attracted other more timid speceis can be scared off. Unless you are free diving or doing the rebreather thing, divers tend to make alot noise underwater anyway.

[pir8]

First I heard this one. I'll have to try it next time out in open salt H2O

[Old Diver]

Dive buddy was trying it off Palm Beach 2 weeks ago...when the reef shark rolled his eyes back it seemed better to stop.

[seaducer]

The only time I have been on a feed dive, a plastic bottle was what they brought the bait down in. Is it possible that you were close to a site where sharks are fed, and that the DM is replicating the sounds that the sharks key in on to signal dinner?

[pir8]

The only time I have been on a feed dive, a plastic bottle was what they brought the bait down in. Is it possible that you were close to a site where sharks are fed, and that the DM is replicating the sounds that the sharks key in on to signal dinner?

I don't remember them crunching that plastic bottle

[carcharodon15]

the unsual sound atrrracts them. the fact that sound travel five times faster underwater also helps

Shark Attacks - And How to Avoid Them (http://www.shark-attacks.info)

[TwoBitTxn]

I'll have to try this at Stetson bank (if I can remember).

[mobula]

Yes and no. At some places we tried it. Once, grey reef sharks came out of the deep blue. Also some reef fish will be attracted.

[Wayan]

Yes used it all the time in PNG and Indonesia, does not work for all species and then can become accustomed to it and not come in as well

[Jupiter31]

Gotta try this next dive......

Interesting, and if it does not work, no big deal

I'll report back

[Scuba Monster]

I wonder if the crunching sound of a plastic bottle underwater possibly simulates the sound of a weakend, thrashing, dying fish (i.e., prey), thus attracting the shark ... just a thought.

[Selachimorpha]

A friend of mine used this succesfully with Blacktips in the Bahmas. I have since used the crunching bottle on numerous dives with Bull Sharks and it worked every time (also had the occasional tuna coming to investigate).
I have yet to try it with any sharks here in the Red Sea, but will give it a go soon!

[Bubble Junky]

It's worked for me with grey reefs in Thailand, Sipadan & Palau......

[lemon]

I heard about this trick from my DM in Belize earlier this month while diving out at Gladden Spit. He said it is very effective at bringing in sharks and didn't want anyone trying it on the dives.

[Krazyklaws]

I've heard that using an empty bottle to 'pulse' water can attract sharks, although I've never tried it. As someone mentioned earlier, it's supposed to mimic an injured, thrashing fish.

A couple of taps on a tank with a knife worked like a charm in attracting hammerheads at Daedelus earlier this month though! They are very curious and come to see what's going on.

[DevonDiver]

I used crunching bottles to attract sharks in Thailand, Malaysia and Philippines. If sharks are in the vacinity, then it does a good job of bringing them into visual range.

My theory is that a crunch bottle might sound like feeding (chomping).