Hasselskog’s goal is to achieve very high wave stability. The engineer believes it is possible and not too complicated to ride through four to five metre high waves on foils. His mathematics expert from India is already working on learning systems to predict wave movements. Future technologies will quickly bring better solutions.
The most important thing for Gustav Hasselskog is to be able to build a cheap candela in the future. All the technologies used are still very expensive and the materials are also quite expensive. In order to really save energy over a wide area, the boat must become cheaper, otherwise it will only be a toy for rich people, says the inventor. It’s like Tesla’s electric car, the „early adopters“ made it possible for many people to buy it today. The Swede would also like this for the Candela, whose name derives from the physical unit for luminous intensity.
But how does the first foil-end motorboat drive? We drive from the shipyard on Lidingö before Stockholm to the nearby harbour, where the Candela is located at the jetty. It is a late autumn day, grey are the water and the sky, only on the shore the trees shine.
In the water, the bowrider looks like a normal small motorboat. Gustav Hasselskog and Alexander, his marketing man, step over with me. It is striking how stable the 7.70 m long boat lies in the water and does not bend when the three of us are standing on one side. The foils, which are at a depth of 1.30 meters across the hull, stabilize the boat.
Before setting sail Alexander and I pull the plug, start the electrical system of Torqeedo and set sail quietly. On the large display all essential data are clearly readable: consumption, speed, range and the inclination angle of the boat. Under our feet lies the large BMWi-3 battery in the center of gravity, the boat is built around it, so to speak. The Bowrider has two benches in the bow, four chairs in the cockpit and a bench in the stern.
The outboard motor, a Torqeedo Deep Blue with 55 kW, is located in a special chassis with very special characteristics. The shaft of the propeller is at the same time the stern foil, a fin that runs across the propeller and lifts the boat aft.
Alexander and I take off, Gustav takes the second candela for the photo shoot. Already during the manoeuvring in the harbour a high stability in the driving behaviour shows up. It feels firmer, but also a bit slower in the rudder. We accelerate slowly outside the harbour, the water is smooth, we have hardly any wind in the bay. I take over the rudder. Slowly I accelerate: Five knots, ten knots, at thirteen knots – about 24 km/h – I feel a slight jerk and the boat gently lifts itself out of the water: We film.
Below us lies about half a meter of air between the keel and the surface of the water. The sailing feeling is light and quiet. I need a bit to get used to the completely new feeling of floating. I accelerate to 20, 25 knots and find the best cruising speed at 23 to 25 knots. The boat is so stable that I can let go of the wheel and go straight ahead like an autopilot. I accelerate further to 30 knots – top speed. The stable driving feeling remains the same, only the driving noise gets louder because water splashes under the hull.
I take a turn, the boat reacts a little slower than a glider hull. I draw the circle tighter. At an angle of 12 degrees, which I read from the display, the electronic system slows me down. That’s what I wanted. If the angle became steeper, the foil would come out of the water, air would interrupt the negative pressure and tilt the boat to the side. Turning is different with a foil boat. With the exercise the safety comes with the fun. It feels great to float.
A little more courageously I take the wave of a passing boat and feel hardly movement in the Candela. That is extraordinary. I test the reliability of the foil by removing the throttle. The boat gently sinks back into the water and I immediately notice the resistance, accelerate again or better thrust. The candela lifts again out of the water. This of course costs energy.
If we drive consistently energy-saving, the boat will manage 50 nautical miles, i.e. 80 kilometres with one battery charge. As a conventional boat, the Candela would only be able to cover about a quarter of the distance, and by no means as comfortably. But with the foils you float wonderfully quietly and energy-efficiently – to the summer house or much further away.
Technical data Candela Seven
Hull material: Carbon
weight: 1.300 kg
length: 7,70 m
width: 2,40 m
Draft: 0.50 m in shallow water mode, 0.40 m in foil mode, 1.20 m without foil
Passengers: 6 persons
Speed: 22 knots (cruise), maximum 30 knots
Range: 50 nautical miles at 22 knots, 8 nautical miles at 5 knots
Engine: Torqeedo Deep Blue 50 with 55 kW
Battery: Deep Blue BMW i3, 40 kWh
Charge: full charge in 12 hours at 230V/16A
Price: 245.000 Euro net