By: Scott Way
It's no longer a secret that boats are transitioning towards electric power. The technology still lags behind consumer needs but the move is seemingly inevitable as manufacturers continue to increase electric components in their products. Mercury announced plans to introduce electric outboards by 2023. Sea-Doo will have electric options across their entire PWC lineup by 2026. Silent Yachts, already a fully electric catamaran builder, is borrowing tech from Volkswagen to increase capabilities. Even the Silicon Valley crowd is getting involved (or at least the Canadian equivalent) with Taiga PWC's going public thanks to a huge push from investor backing.
Sweden's Candela Boats may not be a household name in North America yet, but that's fixing to change. The company's C7 Model has range capabilities that are beginning to attract attention. The biggest impediment with electric propulsion in its current form is that increased drag caused by water drains power and limits range. The C7 circumvents the issue by utilizing a hydrofoil system to create a low-drag propulsion system that not only increases range potential, but also produces a smooth and efficient ride. The C7 is already in production, too, having passed Sweden's requirements for alternative power manufacturers.
Hydrofoils by nature are designed for efficiency. The concept is already catching on with related activities like wakeboarding and stand-up paddleboarding as they add foils to existing designs. The mechanism reduces hydrodynamic drag to a fraction of what a full hull would generate, allowing users to travel faster and more efficiently. When applied to a boat, the reduced drag means less friction driving down the power in the batteries, which means a longer range and more freedom. Gasoline carries much more energy per kilogram than a lithium battery, and until that ratio can be brought closer together, the hydrofoil gives electric boats the potential to compete alongside their gas-powered friends.
The result of the hydrofoil C7 is a top speed of 30 knots (35 mph, 56 km/h). On a single charge of its 40-kWh batter it has a range of 50 nautical miles, or 57 miles (93 km). Is that the same range as an equivalent gas boat? No, but that's three times more than other electric boats on the market with a comparably sized battery. Other designs like the Sarvo 37 have a longer range at 100 nautical miles (114 miles, 186 km) and a higher top speed of 70 knots (80 mph, 128 km/h), but the battery is nine times the size of the C7's 40 kWh powerplant with a whopping 350 kWh platform. Those are figures are also beyond what a recreational boater would need for enjoyable cruising around their cottage or favourite waterway, That's not to say much about 'wants,' however.
There are other incentives, too. The C7 is nearly silent while underway, meaning you'll be able to enjoy a calmer boating experience with reduced noise and less wave effect. It also produces almost no wake, so comparatively speaking you can move quietly and with less disruption than your gas-powered contemporary.
Speaking of the ride, this is where the C7 shines. With the hull's elevation while foiling any wave less than 3.6 feet (1.1 m) will pass directly under the boat. This means larger bodies of water aren't out of the C7's available playgrounds, and the boat can still maximize its range and capabilities under less than ideal conditions.
Now, the drawbacks are the need for a custom trailer for hauling, and some limitations caused by shallow or weedy water. The C7 has a draught of 1.5 metres (4.9 feet) when not foiling, and 1.0 metres (3.3 feet) while foiling. However, the foil system is retractable. The front fully retracts into the body of the boat using electric actuators. The rear foil retracts with only the propulsion unit left below, so while there is clearance to consider it's not significantly different than a parallel outboard design.
There are other perks, as well. The C7 has an available payload of 800 kg (1760 lbs), which is in line with a contemporary gas powered unit. The C-7’s digital flight controller is also an impressive piece of tech. The system uses ultrasonic sensors, gyros, accelerometers and GPS to measure the position, speed and acceleration of the boat. This data is transferred to foil so it can automatically adjust at a rate of 100 times per second to maximize performance and ensure a smooth ride. This is a necessity, especially as new users get familiar with the boat, as the skills needed to captain a foil boat require a new skillset that can't be replicated elsewhere.
As with any forward-thinking design, the luxury of ownership does not fall on the lower end of the scale. The C7 starts around US $240,000. For boaters operating in midsize water in either coastal and inland waterways there is a sizable market for the C7's applicability. Silent sunset rides, a reduced environmental impact, and the head-turning pride of ownership will no doubt be mentioned on the sales floor.
You can check out the C7's capabilities in the video below: