If you've ever tried packing snorkelling gear into a suitcase, you'll know that traditional fins take up an awful lot of space. That's why Folding Fins were created, as they fold down to less than half their regular width when not in use.
Currently the subject of a Kickstarter campaign, Folding Fins were developed by Polish startup Exotech Innovations.
Each fin features a rubber base that is split laterally down the middle. The two halves of that base are linked via a couple of hinges located beneath the user's foot, and by a flexible elastomer membrane that constitutes the midsection of the fin's blade. When the fins need to be packed up, the two halves of each one are simply folded in toward one another like a book.
Once it's time to use the fins, each one is unfolded so it sits flat on the ground – a recessed latch on its underside holds it in that configuration. Wearing neoprene socks or booties, the user then places their feet in each fin's mesh foot pocket. The dimensions of those pockets can be adjusted to the size of individual users' feet via a four-point mechanism, then locked into that sizing utilizing an included titanium key.
Grip pads on the undersides of the fins help keep the user from slipping, if they have to walk across a slick surface to reach the water. Once they start swimming, lateral channels along the outside edges of each fin's blade reportedly help direct the flow of the water. In fact, according to Exotech, the fins were developed using a motorized robotic human leg that was immersed inside a recirculating hydrodynamic flow tunnel.
Each fin is 23.7 inches (60.2 cm) long, 11.6 in (29.4 cm) wide when in use, and about 4.5 in (11.5 cm) wide when folded – the lattermost figure includes the mesh foot pocket, which can be squished down for transport. A pair of the fins is claimed to tip the scales at 3.7 lb (1.7 kg).
Assuming Folding Fins reach production, a pledge of €122 (about US$135) will get you a pair. The planned retail price is $199.
They can be seen in use, in the video below.
Sources: Kickstarter, Folding Fins