Until recently, the longest distance traveled by an electric boat in a single day had been 79 nmi in 20 h, a world record set in February of this year by Voltari. That mark now stands in second place, after a recent endurance test saw the C-8 electric foiling boat from Swedish electric boat maker Candela cover an astonishing 420 nmi (777 km) in 24 h.

“This feat shows that fast, electric waterborne transport over long distances is viable today, not a distant future,” said Gustav Hasselskog, Candela’s CEO and Founder, who piloted the C-8 during the record attempt.

The key to Candela’s success is hydrofoiling. While conventional planing electric boats are usually limited to shorter ranges due to water friction, the C-8 uses hydrofoil technology—wings slung under the hull—to reduce energy usage by 80%. This results in a range that’s two to three times longer than that of traditional electric boats.

The C-8 can also be DC-charged thanks to Candela’s partnership with electric car company Polestar, which supplies both batteries and charging for the boat. Candela says this partnership makes extended journeys using battery power feasible for the first time.

The record run by Candela was enabled by Northvolt’s Voltpack mobile battery storage system, which was used to DC charge the C-8 during the endurance test. Rapid charging was enabled by dock-installed 281-kW·h Voltpack and a Plug DC charger.

The average speed during the 24-h run was 17 knots, even when accounting for charging breaks. The route comprised a 20-nmi loop between Stockholm and Tynningö island, with DC charging after each lap. The distance its C-8 traveled during its single-day endurance test equates to driving from Amsterdam to London and back—or between Trondheim and Stavanger in Sweden. Another comparison a trip across the English Channel between Dover and Calais, which the C-8 could have covered 20 times in 24 h. The company also claims that the C-8 could journey from Stockholm to Finland in 13 h, outpacing a ferry by 3 h.

As with all electrified mobility, energy consumption and costs are key performance indicators in electric boats. The Candela C-8, running at its full speed of 27 knots most of the time, consumed 685 kW·h during its 24-h journey, costing about €110-120 ($117-128) in electricity. In contrast, a conventional gasoline-powered boat would consume roughly 750 L (198 gal) of gasoline, which would cost approximately €1400 ($1494).

Candela conducted the endurance test with Northvolt and Plug to showcase how future DC charging networks for boats could perform in archipelagos and remote coastal areas. Instead of making heavy investments in upgrading the local grid, the test demonstrated that islands can deploy battery systems like Voltpack to ensure enough power is available for fast boat battery charging.

“With a relatively modest investment, charging stations could be built to fully electrify marine transport in the Stockholm archipelago,” said Hasselskog. “For a few hundred million euros, a charging network covering Europe’s coastal passenger transports would become a reality.”

During the 24 h, the C-8 charged for a total of 313 min and received a total of 615 kW·h of electrical energy. Each charge took about 18 min, and the battery was charged from about 13% to 66% at an average power of about 118 kW.

The C-8 measures 8.5 m (27.8 ft) long and 2.5 m (8.2 ft) wide. It weighs 1750 kg (3858 lb) and can accommodate eight passengers including a driver.

Candela is also electrifying larger boats. This Fall, the company will introduce its new passenger vessel, the 30-person Candela P-12 Shuttle. This vessel can operate on most of the world’s coastal waterways while offering a sustainable and cost-effective alternative to today’s fossil-fueled waterborne traffic, which accounts for 3% of global GHG emissions.

The company believes cleaner sea transportation is achievable in the near future.

“We don’t have to wait for tomorrow,” said Hasselskog. “We have the technology to shift towards sustainable marine transport now.”