Hydrofoils and Sharks?

[RickI]

Do the acoustics of planing foilboards attract them or merely improve the visibility so that sightings are more regular? In effect are sharks often in the background in some areas and we just don't notice them as much on other lower board types.

A kiter was bitten on the foot by one a few days ago in Florida seconds after wiping out. Fortunately, it was a rapid taste and run attack with limited damage to the kiter.

Around the same time another kiter in Florida captured a video clip of a small shark making an attack run on his board while planing.

What have foilboarders experienced in this regard? Some have said they strike sharks at times, was this while they were zoning out or swimming intercepts on the kiter I wonder? I have not uncommon encounters while on twin tip boards and directionals. I will say the sharks don't seem to stay interested for very long or move very fast in my experience on those boards.

It would be good to learn more.

More about the attack, incident on video and other observations:

HERE


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[shawn13]

This is really interesting. If they are infact attracted to the acoustics or frequencies the foils generate, I wonder if something could be added on the foil the generates a frequency that repels them, kind of like those deer whistles that people can put on their cars.

[Babel]

Sharks eat rays and the front wing of the foil kinda looks like one. Maybe thats the reason why the shark in the video charged at it...

[Laughingman]

This is really interesting. If they are infact attracted to the acoustics or frequencies the foils generate, I wonder if something could be added on the foil the generates a frequency that repels them, kind of like those deer whistles that people can put on their cars.

I'm thinking laser beams....

[cleepa]

It's a bit hard to conclude anything from one incident. It may have nothing to do with the hydrofoil at all.

[Hawaiis]

Studies have found sharks are afraid of poison sea snake, so a contrasting sea snake pattern was put on the foil strut.

[tautologies]

What studies?

Nice writeup Rick.

[CaptainArgh]

What studies? ....

The SAMS Warning™ pattern is designed to overtly present the wearer as unlike any shark prey, or even as an unpalatable or dangerous food option. At the very least this will provide the user with increased protection, but it could also provide the time needed to evacuate the area if a shark is in range.

We can probably solve the problem by putting these things on the leading edge of the foils...

[tautologies]

I'm asking because as far as I know there is no scientific consensus on it...in fact poisonous sea snakes are on the menu for tiger sharks in areas where there are sea snakes. They eat a lot of them.

The people making the patterns on the wetsuit argued that because sea snakes aren't on the menu for most sharks therefore the pattern somehow works...I think it is nonsense.

[RickI]

There has been more than one report of a shark - foilboard encounter, actually a number of them online anyway. I suspect it may be something to do with the foil acoustic emissions as opposed to improved visibility of shark approaches offered by a foilboard but that is just a impression for now. I do think shark encounters may be more common on other types of kiteboards in some areas than we may realize. I have been approached by several which I caught on my kite GoPro. In deeper, more turbid or darker water, I would likely have missed seeing them. I wasn't aware of any sharks being present during the session. On a recent 45 mile run up the coast, I saw quite a few sharks without a camera and came close to running over a couple of them. Seen or not, the sharks in large measure seem to leave us alone with the odd exception with regard to attack.

Thank you Alex. I did an article on the banded shark suits a couple of years back, at:
viewtopic.php?f=1&t=2381225&start=0

The manufacturer talks a little bit about research in this area in Australia at the link below. I didn't find what was discussed to be all that compelling, a common problem with shark repellent devices over the decades. http://www.sharkmitigation.com/the-science.html

Deers may be easier to spook than sharks motivated by signals suggestive of imminent prey. I know the Navy has been working on acoustic shark deterrents from decades. I don't know that they have come up with a good solution in that area yet.