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DARPA Develops Dolphin-like Tail For Divers
willatnewscientist writes "Forget flippers, the latest idea from the guys at DARPA is a tail-like prosthetic for divers. The (forward-facing) tail, demonstrated at DARPA Tech 2007, is designed to help a diver maintain a speed of 2 knots for up to 300 metres. 'The unpowered, carbon-fibre structure straps to a diver's shins and is used with a motion that is not unlike the way Patrick Duffy swims in The Man from Atlantis. The design is inspired by the way mammals like Seals and Dolphins swim. I caught this video of Powerswim (3.5 MB .avi) at the DARPATech 2007 gathering in Anaheim, California. It would be nice to grab one and try it out when I next head down to the beach, but unless its designers DEKA (the same people who make the Segway) come up with a budget version, the $500 price-tag is going to keep me firmly in my flippers.'"
But it reminds me of this gadget I saw on TV somewhere. Its like a bicycle for travelling on water. It has the same two submerged wings but the rider sits above the water and pounds the machine up and down to keep moving (and dry).
This is a beautiful device. Short cord wings are always better once the materials are up to the job.
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I guess they are expecting that you have to be old enough to remeber the show to have money to buy their products. Has anybody in the 20-something age group even seen that show?
No need to click and read the article. The summary *is* the article.
we just need some laser beams.
come up with a budget version, the $500 price-tag is going to keep me firmly in my flippers.'"
Personally, I think that a $500 price tag will result in this gaining widespread use, assuming it's as useful as the article states.
Why? People spend more than $500 all the time on bicycles, surfboards, skis, and other athletic equipment all the time. Matter of fact, I wouldn't be surprised if all the equipment for your typical diver exceeds $2k. A quick search shows new surfboards costing $300-400.
Worst case, it can be rented out to various tourists at $10/day and pay themselves off in well under a year.
I don't read AC A human right
For those of you not as comfortable with knots and meters(and with the help of google)...
2 knots = 3.37561971 feet / second
300 meters = 984.251969 feet
So it's about 3.4 feet/s over 984 feet.
Takes about 289 seconds, or 4 minutes 49 seconds.
Honestly, that's not as fast as I'd expect from DARPA equipment. Nor does it really have great endurance. *shrug* It's cool, don't get me wrong, but it seems like it'd be a long way away from USEFUL except in very, very specialized situations. Help me out, I can't actually think of any times where you'd want something like this if it only lasts 300 meters. In the time you're strapping that to your legs I'll already have swam most of the way there at a leisurely pace(and as a bonus, I don't have some dolphin fin to remove when I arrive.
Not a lot of information available, but found this http://www.darpa.gov/dso/thrusts/bio/biologically/ powerswim/index.htm/ that states that this device is 85% efficient, whereas typical recreational fins are only 10% efficient. Interesting, but does that mean that the device is going to be 75% more difficult to use that regular fins?
Ahhh, what an awful dream. Ones and zeroes everywhere... and I thought I saw a two.
Mmmph. I dunno. This thing seems like an invitation for a shark to presume you are a nice, big fish.
Not to sound paranoid or anything, but I guess I'll let other people use them for a while first. ;-)
I've fallen off your lawn, and I can't get up.
They Call Him Flipper! Flipper!
Faster than lightning!
No one you see, is smarter than he!
And we know Flipper
Lives in a world full of wonder,
Lying there under, under the sea!
Everyone loves the King of the Sea
Ever so kind and gentle is he....
The monofin is longer and narrower so it has more parasitic drag. This device is more like a high aspect ratio sailplane wing, while the monofin is at best like an old style hang glider.
http://michaelsmith.id.au
As noted: 300 meters in 4.7 minutes. Uh, how many people can hold their breath for just under 5 minutes? Wait, I'll answer for you: Not even many SEALS I know can hold out that long without moving. This is really a piece of combat equipment to be used with oxygen and not for tourists OR a novilty. Swimmers already have monofins that can propel you "almost" as fast.
I hate slashdot
Outrun a shark? At 2 kph for 300 feet?
Methinks you aren't very familiar with sharks. A blue shark for instance is good for about 39 kph. In other words, if it wants you, you'll be had.
I've fallen off your lawn, and I can't get up.
Lasers!!
I want to play Free Market with a drowning Libertarian.
According to The Register, the new fins will allow a diver to swim at a sustained 2 knots.
According to the first link returned by Google for "How fast can a great white swim": A great white's can swim about 20 knots -- in bursts. But, they usually swim around 1 or 2 knots.
So, the question is, who's got a better burst, a diver or a hungry shark? And who do you think can sustain that for longer?
Not too long ago, the Cincinatti Bengal's wide receiver Chad Johnson raced a horse. If anyone ever wants to race a shark, please let me know. I'm putting money on the shark.
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I'm not sure if the guy patented it but I saw the exact same setup, I believe it was in Popular Science, thirty years or more ago. Dead serious on this one. It had the same front fin arrangement. I remember photos of him testing it in a swiming pool. I think he claimed more than 2 knots but it could have been exaggerated. I seem to remember it being more like 3 or 4 knots.
The Sun audio device handled aLaw/Law audio directly, and since they were the Microsoft of the UNIX world everyone else's "/dev/audio" devices work the same way.
This is like finding a file in BMP or WAV format, you go "oh, that's an oldschool DOS/Windows guy who doesn't know any better"... this is what you get when oldschool Sun/UNIX guys who don't know any better release stuff. It's no biggy... chuckle and move on.
I'll let other people have at it--until they make it possible to not have a giant wing oscillate so close to my nuts. That stupid thing is a castration catastrophe waiting to happen. No thanks.
Constitutional rights may be respected, repealed, or modified; but they must never be ignored.
SEALs turning into dolphins. Sounds like they're going backwards. And what do they do if it's a hot landing?
You don't need to outrun a shark, only the other guy who happens to be in the water nearby.
Personally, I think that a $500 price tag will result in this gaining widespread use, assuming it's as useful as the article states.
;-)
I've been diving for a couple of decades and this includes rare specialties where covering a lot of distance is useful. For normal recreational diving traveling around fast generally indicates a newbie. The point of diving is to enjoy the scenery and as divers become more experienced they generally slow down and become "lazy" and try to leverage currents and surges as much as possible.
A dolphin kick is something that divers occasionally do with normal fins to vary muscle usage and avoid fatigue and cramps. So many of us are somewhat familiar with the general style. The problem with this style is that it is quite limited with respect to maneuverability. Divers often use their legs/fins asymmetrically or at odd angles. This far more useful than going fast.
Finally, anything that makes your silhouette look even more like a seal to a shark is a bad idea.
For the ammount of energy expended to move forward, as the other posters stated, no. It actually will take less effort to go faster, since its more efficient, thus more of your exerted power goes to moving you forward.
From a usability aspect, after watching the video of it in use, I have to say YES, it will be more difficult. Besides remembering to not extend your legs so far that the thing will hit you in the nuts, as you bring your legs back it extends down and away from you, just waiting to snag stuff on the bottom. This thing would only be good for swimming pools and open water where you have no intention of getting near the bottom.
SCUBA divers have a hard enough time as it is controling bouyancy so they can stay at a position close to the bottom without kicking up silt or breaking the delicate reefs. Having something like this just asks for trouble, and I seriously doubt any practial use for SCUBA exists. This being a DARPA project though, its more likely for military use such as covert SEAL ops requiring faster underwater swims. There it definately has potential, so long as they can shrink it down so its as small as/smaller than current fins when stowed, and can be put on/taken off just as quickly.
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This DARPA thing appears to be nothing more than a copy of the famous Aqueon invented back in the 1960's. You can find videos of it on YouTube, and even the original patent drawings are online which you could use to build your own: http://forums.deeperblue.net/freediving-equipment/ 53592-weird-fin-long-ago.html
Just google 'Aqueon swimming device'.
Swimming Machine
"Flex your legs, then kick out -- the Aqueon swimming machine enables you to out-speed an Olympic swimmer, says Pan Western Research. As your legs move, the forward plane rises and falls." -- Popular Science
(Popular Science, "What's New", June 1974)
You can see the old flyer at Innerspace Corporation.
Spoken like a true Jaws watcher who's never actually seen a shark in real life. I have, and I can tell you that it's *damn* hard to get anywhere near them, as they are far more afraid of you than you are of them.
You're also wrong about shark vision, many sharks have excellent vision. They are also quite intelligent, research (that I can't be bothered finding links on) has demonstrating sharks solving problems that were previously thought to be beyond them. They're not exactly going to be April fooling Flipper, but they aren't the mindless ocean dwelling mulchers that you seem to think they are.
Sharks also almost uniformly go for dead or dying fish. They are predators of opportunity. Only the great white is a habitual predator, and even then it will not attack prey that it feels can fight back. So in short, if you have a tiger, bull or bronze whaler shark circling you and eying you the way you'd eye a McDonalds burger (although I think the average human would be healthier than McDonals), swimming confidently towards it would likely scare it off. If not, a punch in the nose or gills is almost certain to do so. I'm not saying it's foolproof, but its better than scrambling to the surface like a panicked seal. If you have a great white circling you, looking hungry, the same tactic would work, only pray first. Jokes aside, sharks of any species are hard to approach. If you're diving and you see one, you're lucky, not unlucky. They can sense you well outside visible range, and they know you're not food and will avoid you before you even knew they were there. I really wish I saw more sharks on the dives I've done, and plan on going shark watching more. They truly are beautiful creatures.
We don't look anything like food they're used to, we smell funny, give off all kinds of weird electrical signals with all that metal gear we carry and we certainly don't taste good, which is why most attack victims survive the first exploratory nibble, as the shark wrinkles its nose, thinking "eew, human" and goes off to find a tasty seal. If the shark wanted to eat the surfer, we wouldn't be yelling "jeez that surfer got attacked!", we'd be mumbling "I coulda sworn there was a surfer there a minute ago".
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A-law and u-law are used for compression of voice in phones and the like.
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So DARPA has developed the AQUEON, http://www.abc.net.au/tv/newinventors/txt/s1106609 .htm , which was actually developed by an Australian in the 70's? Got to make you wonder why no one in our government every checks to see if they are giving out grants for developing stuff that's already been patented. I wonder how much we paid to "develop" something that was probably taken from the original inventor's patent drawings. Sounds like there wasn't much actual development work done, to me. I wonder how big the grant was.
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The monofin (backwards pointing) http://en.wikipedia.org/wiki/Monofin has been around since the Soviets introduced it in the early 70's.
I can't see how this new thing will generate any more thrust, or more efficient thrust than the monofin does, and it has to suffer from the same basic flaw, you get lots of thrust, but sacrifice maneuverability. (not to mention the monofin isn't going to crack you in the nuts.....)
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Not sure exactly when but I watched an article about this on Tomorrows World a BBC science program sometime between May 1965 and September 1967 (That was the period that my family were based in Northwood. I know it was then because I wanted one and tried to make my own in the workshop that house had).