Champion sailor pitches electric hydrofoil ferries for Sydney Harbour

“What’s changed since those days,” Mr Percy said, “is modern computers, the ability to autonomously control things rapidly to model different sea states with accuracy.”

Unlike those passive hydrofoils, Artemis’ eFoiler is modelled on an aircraft wing with a built-in electric motor and propeller. Its flaps can move thousands of times a second to ensure the vessel’s progress is as smooth, stable and efficient as possible.

Mr Percy credits many of the advances to the America’s Cup, even though it looked to many to be merely a bunch of billionaires having a good time. “Whenever money is not such an object and when competition is what’s driving you, you end up making large technical advances.”

And how broad can this technology be? Mr Percy said ocean liners would require foils of almost unimaginable size, but a 300-tonne, 350-seat ferry was plausible. Artemis’ first ferry will seat 150 people.

Mr Percy, who studied economics before his sailing career took over, admits an Artemis ferry cannot compete financially on short, slow routes. But where higher speeds – 30 knots-plus – and slightly longer distances are involved, such as the famous route between Sydney’s Circular Quay and Manly, it comes into its own.

The cost of an eFoiler ferry is up to €11 million ($18.5 million), compared with €6 million to €7 million for a new diesel model. However, Mr Percy said Artemis modelling showed that, running all day between Circular Quay and Manly, recharging in short bursts while passengers disembark and board, it could pay off that extra cost in about 2½ years, without subsidies. It would also be smoother, quieter and cleaner, while creating far less wake and zero local emissions.

Two small Sydney Harbour ferries were converted from diesel to electricity in 2021 to provide a shuttle between Barangaroo and nearby Pyrmont. The NRMA, which operates the service, says they save “40,000 litres of diesel a year and 100 tonnes of CO2 emissions”.

Mr Percy said a typical high-speed harbour ferry produced about 8000 tonnes of CO2 a year, and that could drop to about 250 tonnes with e-foiling technology.

Artemis, a private company of which Mr Percy is the largest shareholder with about 40 per cent, is one of many working on electric boats for waterways or close-to-shore operation (limited range prevents true long-distance running at this stage).

New Zealand’s EV Maritime is building two 200-passenger electric ferries for Auckland Transport. Tasmania’s Incat, which has had international success with its large vehicle carrying catamarans, is currently building a massive electric ferry with room for 2100 passengers and 225 vehicles. Needless to say, it won’t foil.