The Concept

The Sirène is a single-passenger kayak propelled by an innovative biomimetic propulsion system that imitates the movement of a dolphin’s tail. It also features a driverless computer that can take you on a ride around the lake whilst you’re enjoying the view or simply reading a good book.

The Background

Kayaks and pedal boats have been around for a long time. They are fun to ride, but you still need to pedal and steer them to cruise around the lake.

It wouldn’t hurt to increase the efficiency of their propulsion system, harness the sun’s energy, and integrate a driverless feature to enjoy the rides a little more. That’s the idea behind the Sirène concept.

How it Works

Let’s start with the oscillating propulsion system (OPS). Imagine the tail of a dolphin, which moves up and down. The resulting force pushes the dolphin’s body forward. The rotation of pedals or an electric motor would thus be converted on the Sirène to move the craft. This system would be similar to the Iruka outboard engine concept (See the video).

It would also be possible to change the amplitude of the movement, the speed, and the surface and shape of the foil. These changes would be balanced based on the user and the craft, but it is believed they could save up to 25% in energy, letting you go farther or faster during your ride.

The Sirène would use three modes of energy: solar, electric, and mechanical. Two packs of ion lithium batteries located inside the hull would store enough energy for a 6-hour long ride. The automated navigation system would also be protected within the hull.

The first source of energy would come from flexible solar panels located on the deck of the Sirène. Similar panels could also cover the owner’s dock and charge the Sirène’s batteries while it’s not being used.

The second energy source would come from the power grid. A smart outboard charger would refill the batteries of the Sirène while it’s anchored (plugged to a CFGI power outlet).

The third source (mechanical) is a pedal system that would serve to propel the oscillating rear fin. A dynamo could also be engaged to the pedals to recharge the onboard batteries at the same time.

What’s It’s Used For

The Sirène would be a quiet, personal watercraft. It would not emit any CO2, and it would use the sun or human power to take rides on the lake. There is a demand for clean and quiet watercrafts for ecological lakes. Of course, like any project, this one would need to be developed to meet the performance requirements of customers. Would the innovative oscillating propulsion system be more efficient? Can a driverless system be developed to avoid other obstacles on the lake and stay at a pre-set distance from the shore? The only way to find out is to build a prototype!


The Sirène concept was developed in June 2015 by Charles Bombardier in collaboration with Jan Bujnak, an industrial designer from the Slovak Republic. Jan graduated from the Academy of Fine Arts and Design in Bratislavia and works as a Freelance designer. Jan has also produced the concept images for the Biora emotion sensing bike and the Pegasi propane car.