Candela is really something else. We tested this electric boat that you can use just like a normal boat. It’s a 7.7-meter bowrider to navigate for two hours at 25 knots. It can reach up to 30 knots, if I wish, and at cruising speed (and including the reserve) it has over 58 miles of autonomy. Design with a Nordic and essential style, Candela Speedboat is as traditional in shape and category as it is innovative under the waterline. Not just for foils, but for how foils behave. The foil control system makes the boat efficient and easy to use. Let’s go in order.
There are two hydrodynamic profiles. The first, with upside-down double T, is placed in the center of the boat. Its presence is revealed by the two columns (“strut” or “shaft”) that are placed in boxes that also serve as a support structure for the four armchairs of the cockpit. The box is necessary to move the foil so that the draught changes from 1.2 meters with external foils to 0.4 meters with the foils raised. The draught in navigation, of course, is reduced when the boat begins to foil. The second submerged surface for hull lifting is at the end of the outboard stalk Torqeedo Deep Blue 50R (80 horsepower equivalent), powered by the BMW i3 battery 40 kW.
All about the foil control system
To make the set work there is a complex software that receives information from the environment and uses it to adapt the position of the foils to navigation. In part, the boat behaves like a cetacean with its sonar system. A pair of transducers placed at the bow, through ultrasonic pulses, understand how the boat is positioned on the sea surface and how the position changes over time. This happens about 100 times per second. The data is then sent to the calculation system that changes the position of the foils so that the boat is stable (and above all perceived to be stable) during the navigation.
Thus the transition between displacement and foiling navigation, which takes place at about 17 knots, is perceived as natural and not as something alien. The sensation of total silence when we are dropped off at the quayside to get away from the mooring is something very strange for those who are used to the sound of classic engines. And the absence of noise, or rather, its extreme reduction is a peculiar element. The electric motor when pushing the boat is not totally aphonic, even if it is immensely more muted than an internal combustion engine. But the absence of lapping between water and hull is the main reason for the silence. And in fact, when you turn aft sailing in foiling you do not see a real wake, but three thin parallel lines that plough the surface of the water.
How to drive Candela
When we tested some other foiling boats the feeling in maneuvering was like of being on a tricycle (turn right and you feel pushed to the left). Candela Seven is not like that. When you turn the boat tilts towards the inside of the curve and not towards the outside as, for example, a car. The merit is always the software-hardware system created by the Swedish company. The display of the driving position, user interface of the entire boat, in addition to navigation data and maps also shows the degrees of lateral and vertical inclination of the main foil. During the take-off and landing phase, it is evident that Candela’s brain adapts the position of the appendix according to the position and state of the boat. The pilot just manageswith the throttle.
Low consumption, 20 cents per mile at 25 knots
The low consumption is the reason why this bowrider can sails fast and for a “long” time. Its navigation in foling is extremely efficient. Just for reference. A 40 horsepower outboard to push a 5.8-meter rib at 28 knots consumes about 20 liters of gasoline per hour, or 0.71 liters per mile for a cost of about 1.30 euros per mile. At 25 knot with its 40 kW of power Candela can navigate about 50 miles, which means it needs about 800 W per mile. Translated into economic figures, since the final cost of energy to the user is about 0.25 €/kWh the cost per mile is about 20 euro cents. Of course, to return of the 245.000 euros plus VAT of his purchase you have to sail a lot. But the first 10 models have already been sold and the Scandinavian shipyard has already predicted that in 2020 will build 40 boats.
For recharging, the home electrical socket at 220V/16A is sufficient and in 12 hours the batteries return to full potential. And the company guarantees their full functionality for 8 years.
Technical data Candela Seven
- Lft. 7,70 m;
- b.max: 2.40 m
- Weight: 1300 kg
- draught: 0,4 (foil lifted)- 1,2 (foil immersed) m
- maximum speed: 30 knots
- more efficient speeds: 19-23 knots
- minimum foling speed: 17 knots
- range: 50 miles + 8 miles at 3 knots