Blowing established truths out of the water

In 2014, a task force was assembled, consisting of some of the world’s leading experts within dynamic modelling, hardware design, hydrodynamics, control theory, machine learning, image & signal processing, structural engineering and electrical machines. The mission was to make electric boats that would offer the elusive combination of both range and speed. Up until then, all electric boats either had very limited range or very low speed, due the inherent inefficiency of conventional boat hulls. Solving this crux would radically change the performance boundaries of electric boats.

After 10,000+ hours of simulations, design iterations and sea trials, the first electric hydrofoil boat was born.

At the end of 2016, a full-scale prototype was launched, fulfilling the target of making an electric boat with a range of more than 50 nautical miles per charge at a speed of 22 knots.

We make a large percentage of the components in our own factory in the Stockholm archipelago where we also assemble and perform final testing.
The hardware necessary for exact & instant flight control had to be developed in-house at Candela to achieve the demanding specifications.

Tech details

The innovation formula

No planing electric boat can travel more than 30 nautical miles at high speeds due to enormous water friction loss. The secret to long all-electric range at sea lies in massively reducing friction by adopting hydrofoils, minimizing weight and using an electric drive train with revolutionary performance. Here is the technology that enables the Candela C-7 to fly above the waves.

C–Foil System

The Foil System fitted in Candela C-7 is made entirely from carbon composites and uses design principles from the aviation industry.

Hydrofoils remove 50% of the drag compared to a planing boat. This is the most important principle in our design. Hydrofoils can be designed in different ways with varying efficiencies and behavior. We opted for the most efficient and precise solution possible, which is fully submerged foils.

Other types of foiling systems are less efficient and are therefore not suitable for electrification.

Similar to a traffic airplane, C-7 uses a large, straight main foil close to the center of gravity and a small T-foil in the aft. The foils are retractable for trailing, storage, and shallow water operation.

Ultra-light build

On a weight to strength ratio, carbon beats glass fiber by a wide margin.

Batteries are heavy. In order to make up for this, we needed to make the hull extremely light, while still rigid and strong. The solution was to make it out of vacuum-infused carbon fiber, which allows the C-7 to weigh 30 % less than a similar boat of the same size.

Propulsion unit

The in-house designed propulsion unit is unique in its very low hydrodynamic drag coefficient.

No existing electric outboard could achieve the hydrodynamic efficiency and power output required for Candela C-7. Therefore, we created an ultra-slim and streamlined lower unit, engineered to be the most energy efficient outboard ever .

The efficient propulsion in Candela C-7 coupled to hydrofoils results in a 20 x reduction in energy consumption per nautical mile compared to a traditional 8-meter petrol boat, at speeds above 20 knots.


The intelligent onboard flight controllers continuously optimize the position of the hydrofoils in response to various sea patterns.

A flying boat with submerged foils needs active stabilization by computers. Candela’s industry-leading software and sensor technology enables safe, comfortable and thrilling driving experiences in various sea states.

The on-board Flight controller automatically adjusts the hydrofoil’s angle of attack at a rate of 100 Hz, resulting in an artificially stable craft that is superior to conventional boats.

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