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.'"

Comments

RTFA

[Anonymous Coward]

No need to click and read the article. The summary *is* the article.

now,

[martinelli]

we just need some laser beams.

$500 - not a bad price

[Firethorn]

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.

Re:$500 - not a bad price

[Anonymous Coward]

Its not uncommon for people to spend $120-$150 on normal fins for scuba diving. Some free diving (holding your breath and swimming to depth) fins can go for over $200. The Omer Millennium Carbon Rekord III has a MSRP of $504 (this sells for $420 online).

So I'd think that a $500 fin if useful could have quite a market. Recreational divers would probably just use underwater scooters if they really needed to go a great distance from their entry point so I'm not sure how hot they'd be on having to kick it themselves. Not to mention that during the fun part of the dive people like to be able to go at a slow speed so they can see things so they'd need to bring normal fins too.

Re:$500 - not a bad price

[gujo-odori]

To put the speed in perspective, 2 knots/hours is roughly double the speed of the world record holder in the men's long course 800 meter freestyle. Even allowing for fins, and for being under water, I rather doubt you could swim that far, that fast, with your legs.

Plus, of course, if a person could swim that far, that fast, with their legs do you really think DARPA would have spent the money do develop this device?

Re:$500 - not a bad price

[malkavian]

I'm a diver, and I'd shell out $500 for a pair.. And yep, my diving kit exceeds 2k. Double that and you start to be in the right area.
Fins are one of the areas that I'd love to be able to get more power from without increasing my fatigue. If someone comes up with a way of doubling my speed, while keeping my air consumption constant, I'd leap at it.
While you're under water, everything you carry keeps you alive, and fins, often forgotten, are critical in keeping you effective in a current. There's been the odd time or two, when I've been caught in an unexpected stream, and being forced to cling to rocks to stop myself being pushed either off course (bad) or down (worse). At times like that, when being faced with a downdraught to 70m or more, you'd gladly pay all you had, and more, just to give yourself the best chance of surviving the dive. Sadly, you don't get the option when the most need it; you have to pay in advance, and hope you never need it..

On the fun side, it'll double your range if you get twice the speed, with no increased air consumption. That means more to see with each dive. Not sure you can do a wreck penetration with one of those on you though. Too much opportunity for it to snarl, and kick up the silt. And one thing you don't want is to be stuck inside a wreck, and have the world go dark (yes, you can get zero visibility quite easily from a badly executed fin kick or two in silty conditions).

Conversions and comments

[Kandenshi]

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.

85% efficiency

[K.os023]

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?

Re:I am eating DOLPHIN right now!

[fyngyrz]

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.

Re:I am eating DOLPHIN right now!

[mobby_6kl]

You don't need to outrun a shark, only the other guy who happens to be in the water nearby.

It's the Aqueon, "What's New" in June 1974!

[ClayJar]

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.

Re:You're forgetting the nose piece...

[MrNaz]

Sharks bite at stuff, it's what sharks do, they are pretty much giant eating machines living in the ocean.

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".

Oops, this was invented in the 1970s

[rben]

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.