The sector of motorized recreational toys is undergoing a massive change because of the availability of new materials, high performance electric motors, new manufacturing techniques, computer aided design, and a new generation of designers that do not know the meaning of the word ‘cannot’.
A suitable example of this phenomenon is the Quadrofoil, created by three young Slovenian designers in less than six months. The Quadrofoil is a two–person electric hydrofoil that runs completely silently with a top speed of 40 kilometres per hour.
The remarkable efficiency of hydrofoils makes it possible for this sports car to achieve a top speed of 40 kmph, with just one 3.7 kW electric motor, and because of its lightweight (150 kg- 330 lb) carbon fibre and Kevlar body and in- built 4.5 kWh lithium batteries, it has a range of 100 km. You can also recharge it from a domestic power point in about an hour or through the flexible solar panels that come with each Quadrofoil and are designed to be folded inside the watercraft as an emergency power source, or to top up the battery when "off the grid."
The efficiency of the hydrofoil comes from its ability to lift a boat out of the water during forward motion, reducing hull drag to near zero into the bargain. With the absence of all that surface area on which any turbulence and drag can exert influence, only a much smaller surface area of the hydrofoils and aerodynamic drag exists to limit top speed. As a result, the speed of that boat that has hydrofoils is either greatly increased, or the amount of power required to take it forward is reduced greatly as compared to a boat without hydrofoils.
One of the key enablers of the machine was the development of a hydrofoil-folding mechanism, which enables the six kilogram hydrofoil legs to be adjusted during use, and to be folded upwards by means of a manual or electric winch before entering a swimming area or approaching shore. Once the hydrofoil legs have been turned upwards, the Quadrofoil has a draft of just 6 inches (15cm).
The folding legs can also be removed, making for an easily transportable machine at 150 kg and 10 feet (3 m) in length.
Due to the low power of the 3.7 kW motor, the Quadrofoil belongs to a category of watercraft that does not require registration, a license, insurance or navigation permit at least in the EU.
Taking things a step further, the makers have used biomimicry to develop the shape of the hydrofoils. Hydrofoils have another benefit – the comfort factor of the passengers. Once the hull is lifted above the waves, the continuous pounding disappears and it feels like the boat is flying. The makers claim that the Quadrofoil is unsinkable, and has been designed to return to an upright position if it overturns or tilts too much in a tight turn.
