Dual blade swim fins have divers kicking with ease

Oct. 19, 2000
Divers, hold on to your swim fins. ScubaPro's innovative Twin Jet fins let you pull, tow, swim, and dive with more control and less effort.

The TwinJet swim fin shown during downstroke. The process is repeated during upstroke.

Key to this design is its dual-blade made from tough, yet flexible, Monprene thermoplastic elastomer from QST Inc., part of Teknor Apex's Thermoplastic Elastomers Div., St. Albans, Vt. According to ScubaPro, the dual blade converts more of the diver's kicking energy into forward motion than conventional paddle-shaped swim fins. Each kick with a typical fin creates turbulence that wastes energy, says the company. With the Twin Jet, however, displaced water flows over the top and bottom of each blade, producing a pressure differential, similar to that which generates lift in an aircraft wing. But instead of lift, it creates forward motion.

Because the fin must flex smoothly as a diver's foot cycles from downstroke to upstroke and back, ScubaPro needed a tough, elastic material that would not only snap back to its original position at the end of each stroke but also resist tearing after constant flexing.

In conventional swim fins, resilience or "snap" is typically provided by natural rubber formulations, but these materials don't sufficiently resist outdoor weathering, say company officials. Synthetic rubber materials, such as EPDM, and many types of TPE can withstand outdoor elements but don't provide enough "snap." Monprene TPEs, on the other hand, are said to be resilient, offering high tensile and tear strength combined with good weathering resistance. Further, Monprene TPEs have a low coefficient of friction, which contributes to low drag in water.

The new concept fin includes other special features that will have divers kicking easily. For instance, vents let water flow through after it passes over the twin blades, while the fin's angular configuration is said to maintain symmetry between upstroke and downstroke. According to ScubaPro, these combined features help reduce diver fatigue and cut air consumption by as much as 40% compared to conventional swim fins.

ScubaPro also offers a special diving fin called the Twin Jet Graphite molded of a softer, more flexible Monprene formulation that is lighter in water than the standard Twin Jet.

Sponsored Recommendations

Altech's Liquid Tight Strain Relifs Catalog

March 13, 2024
With experienced Product Engineers and Customer Service personnel, Altech provides solutions to your most pressing application challenges. All with one thought in mind - to ensure...

Industrial Straight-Through Cable Gland

March 13, 2024
Learn more about Altech's cable glands and all they have to offer for your needs!

All-In-One DC-UPS Power Solutions

March 13, 2024
Introducing the All-In-One DC-UPS, a versatile solution combining multiple functionalities in a single device. Serving as a power supply, battery charger, battery care module,...

Smooth Sorting with SEW-EURODRIVE!

Feb. 22, 2024
Sorting systems are essential when it comes to warehouse automation, material handling, and distribution. SEW-EURODRIVE’s automated sorting solutions increase capacity, reliability...

Voice your opinion!

To join the conversation, and become an exclusive member of Machine Design, create an account today!