In La Rochelle on France’s Atlantic coast, the bus sometimes floats. Since May 2009 the city’s public transport network has run a “Bus de mer” (sea bus) between the famous Old Port with its medieval towers and the Minimes marina. Its two boats, Galilée and Copernic, are electro-solar catamarans, and they were among the first passenger boats with this kind of propulsion.

The catamarans are built from composite materials, and their hull lines were optimised to be as light as possible and use little energy. Each carries 75 passengers at about 6 knots. The batteries are charged from the grid at night, and solar panels on the roof deliver about 15 to 20% of the power during the day. Together this is enough to run all day without recharging. The boats are quiet, emit no exhaust and cost about 7 euros per day for 100 km, about six times less than a conventional boat.

La Rochelle kept experimenting: since 2017 one of the sea buses has been running on hydrogen as a trial, and a second line, the Passeur, connects the Old Port with the Ville-en-Bois district by electric boat. A ride costs the same as a bus ticket.

Solar ferries are now common on European waters. See also Berlin’s FährBär, India’s Aditya and Australia’s Solar Sailor.
Technical data
| Operator | Yélo, public transport of La Rochelle (France) |
|---|---|
| In service | Since May 2009, Old Port ↔ Les Minimes |
| Boats | Galilée and Copernic, composite catamarans |
| Capacity | 75 passengers each |
| Speed | ~6 knots |
| Energy | Grid charging at night + solar roof (15–20% of daytime power) |
| Running cost | ~€7 per 100 km, about 6× less than a conventional boat |
Photos
- Top photo: Jean-Pierre Bazard Jpbazard / Wikimedia Commons, CC BY-SA 3.0
- An electro-solar sea bus in front of the towers of La Rochel… Photo: Jebulon / Wikimedia Commons, CC0
- Crossing the outer harbour on a day with choppy water. Photo: Jean-Pierre Bazard Jpbazard / Wikimedia Commons, CC BY-SA 3.0
- Copernic in summer 2012 on the line between the Old Port and… Photo: Jean-Pierre Bazard Jpbazard / Wikimedia Commons, CC BY-SA 3.0
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