Stockholm rolled out something unusual on its waterways in late 2024, and commuters didn’t take long to notice. An electric ferry that lifts out of the water as it moves started shuttling riders between Ekerö and the city centre. A year later, Sweden’s transport regulators say the pilot didn’t just work, it exceeded expectations.
They found the boat cut emissions by up to 94 percent compared with similar diesel ferries. It also cut the travel time almost in half, dropping a 55-minute trip to roughly 30 minutes. For a city built across 14 islands and stitched together by more than 50 bridges, that kind of time savings is hard to ignore.
Diesel ferries haven’t helped the region’s climate goals either, accounting for nearly half of public-transport emissions. The hope was that Candela’s P-12 Shuttle could show another way.
The early results made local leaders call the project a possible “paradigm shift” for how Stockholm moves people across the water.
The boat itself is different from anything the city has seen. Candela describes the P-12 as the world’s fastest electric passenger vessel in service, and it works by rising above the surface once it picks up speed. Carbon fibre foils tucked underneath act like underwater wings. When they lift the hull clear of the water, drag drops sharply. Less drag means the boat can travel farther and faster on battery power.
A computer system handles all of the adjustments. Sensors read the water conditions in real time and constantly tweak the angle of the foils to keep the ride steady while the boat “flies.”
The design also has a side benefit that matters in crowded waterways. The ferry creates a wake about the size of a small dinghy, according to the government report. Smaller waves mean less shoreline erosion, fewer disturbances to sensitive habitat and a smoother ride for the people on board. Sound readings showed it was as quiet as a car travelling at 45 kilometres per hour and barely noticeable from 25 metres away.
Because the wake is so small, authorities granted the ferry a speed exemption. Stockholm normally caps vessels at 12 knots, but the P-12 can run its route at about 25 knots. That lets the electric shuttle take full advantage of its design.
Ridership responded. Passenger numbers on the Ekerö line rose by 22.5 percent during the trial, suggesting that commuters and tourists were more than willing to swap the slower trip for the faster electric option.
The report also pointed out something city planners tend to watch closely: cost. Charging upgrades for the P-12 were relatively modest compared with what conventional electric ferries typically require. Paired with lower maintenance and no fuel costs, the economics looked promising.
The Swedish Transport Administration ran the numbers on what a scaled-up service could do. Replacing two diesel ferries with six P-12 vessels could raise capacity by about 150 percent, allow departures every 15 minutes instead of once an hour, and generate an estimated SEK 119 million in socioeconomic benefits. That’s roughly €12 million.
Gustav Hasselskog, Candela’s founder and CEO, said the data affirms the company’s bet on hydrofoils. “The Candela P-12 can transform urban waterways,” he said. “By combining high speed, minimal energy use, and near-zero emissions, we can unlock faster, cleaner, and more cost-efficient waterborne transport for cities worldwide.”
Cities are paying attention. Berlin and Mumbai, along with destinations in the Maldives and Thailand, have announced plans or orders for similar vessels starting in 2026.
For Stockholm, the agency recommended expanding exemptions so more routes can use the technology. If that happens, the city known for its bridges may start to rely a little more on the space between them.
