PowerSwim
Encyclopedia
The PowerSwim is a device somewhat like two pairs of long thin airplane wings, one pair at each end of an axis. The axis is fastened to a scuba diver's shins by straps round his legs. The longer pair of wings (about 6 feet (1.8 m) wide or a bit less) is at his hips and the shorter pair is at his ankles. The wings rotate limitedly on axles near their front edges, and thus on upstroke and downstroke they propel water backwards. It is claimed that the length of the front wing lets it operate outside the cone of wake
Wake
A wake is the region of recirculating flow immediately behind a moving or stationary solid body, caused by the flow of surrounding fluid around the body.-Fluid dynamics:...

 that starts at the diver's shoulders. It is claimed to let a scuba diver or frogman
Frogman
A frogman is someone who is trained to scuba diving or swim underwater in a military capacity which can include combat. Such personnel are also known by the more formal names of combat diver or combatant diver or combat swimmer....

 swim much faster (250%) than with swimfin
Swimfin
Swimfins, swim fins, fins or flippers are worn on the foot or leg and made from finlike rubber or plastic, to aid movement through the water in water sports activities such as swimming, bodyboarding, bodysurfing, kneeboarding, riverboarding, and various types of underwater diving.Scuba divers use...

s for the same amount of bodily effort, if used correctly, and being not motorized, it makes no motor noise to be heard by hostile hydrophone
Hydrophone
A hydrophone is a microphone designed to be used underwater for recording or listening to underwater sound. Most hydrophones are based on a piezoelectric transducer that generates electricity when subjected to a pressure change...

s, but noise would occur if the front wings are allowed to hit the diver's hips at end of upstroke. It works somewhat like a penguin
Penguin
Penguins are a group of aquatic, flightless birds living almost exclusively in the southern hemisphere, especially in Antarctica. Highly adapted for life in the water, penguins have countershaded dark and white plumage, and their wings have become flippers...

's or plesiosaur
Plesiosaur
Plesiosauroidea is an extinct clade of carnivorous plesiosaur marine reptiles. Plesiosauroids, are known from the Jurassic and Cretaceous Periods...

's side-mounted flippers. Its estimated cost is less than $500. The diver uses it by moving his legs up and down together, letting the knees bend and straighten.

It was developed by DARPA in 2007.

Aqueon

Aqueon is or was a similar device to PowerSwim. It was primarily developed in the 1950s by the Innerspace Corporation, an aquatic propulsion company which specialized in submersible
Submersible
A submersible is a small vehicle designed to operate underwater. The term submersible is often used to differentiate from other underwater vehicles known as submarines, in that a submarine is a fully autonomous craft, capable of renewing its own power and breathing air, whereas a submersible is...

 thrusters at the time. Its front wings, at least sometimes, are shorter than with PowerSwim. The diver held onto it by trapping it between his shins by putting his shins in the side hollows of two -shaped attachments. The first working Aqueon unit was sold in 1979. Its original designer was California Institute of Technology
California Institute of Technology
The California Institute of Technology is a private research university located in Pasadena, California, United States. Caltech has six academic divisions with strong emphases on science and engineering...

 graduate Calvin "Cal" Gongwer. It was claimed to provide three times as much thrust as conventional swimming fins
Swimfin
Swimfins, swim fins, fins or flippers are worn on the foot or leg and made from finlike rubber or plastic, to aid movement through the water in water sports activities such as swimming, bodyboarding, bodysurfing, kneeboarding, riverboarding, and various types of underwater diving.Scuba divers use...

 and up to six times as much power, and that from a stationary start, a swimmer covered 25 yards in 8.4 seconds using Aqueon, and that with an Aqueon a swimmer covered 1500 yards with scuba equipment in 24 minutes; the fastest time covered by the same diver with scuba equipment and fins was 44 minutes. The Aqueon was reportedly examined at length and during multiple "pool parties" at the Gongwer residence by DARPA scientists before they created their new concept.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK