What its makers say is the world’s biggest boat powered by the sun was unveiled in Germany on Thursday ahead of its planned circumnavigation of the globe in 2011 — the first under solar power.

“This is a unique feeling to see in front of me today a boat which I so often dreamed about,” said Raphael Domjan, the boat’s future skipper.

The sleek, 31- by 15-metre (100 by 50 foot) catamaran, known as PlanetSolar, 35 metres by 23 metres when flaps at the stern and the sides are included, will be “silent and clean,” say its makers, also called PlanetSolar.

The vessel will be able to achieve a top speed of around 15 knots, (25 kilometres per hour), and can accommodate 50 people on its round-the-world voyage.

The futuristic-looking vessel is topped by 500 square metres (5,380 square feet) of solar panels, with a bright white cockpit sticking up in the centre.

Constructed at the Knierim Yacht Club in Kiel in northern Germany, its state-of-the-art design also means it will be able to slice smoothly through the waves even in choppy waters.

PlanetSolar will be launched in late March before starring at Hamburg port’s 821st anniversary celebrations in May and undergoing testing between June and September. The world tour will then start in April 2011.

Silent and clean circumnavigations of the planet were achieved centuries ago using sail power, and PlanetSolar acknowledges that solar power is not about to become the main power source on modern cargo ships.

But instead PlanetSolar says it wants to use the voyage primarily to promote solar power and other non-polluting sources of energy, and to show what can be done.

“PlanetSolar wants to show that we can change, that solutions exist and that it isn’t too late. Future generations are looking to us; our choices will mark the future of humanity,” it said.

“PlanetSolar is a boat equipped with classical technologies available on the market.”

The two-person crew on the 60-tonne PlanetSolar plan to stick as close as possible to the Equator in order to maximise the amount of sunlight to power the vessel.

The roughly 40,000-kilometre journey is expected to last around 140 days, with organisers assuming the boat can keep up an average speed of around eight knots.

The planned route foresees the boat crossing the Atlantic Ocean, slipping through the Panama Canal, crossing the Pacific and then the Indian Ocean, before passing through the Suez Canal into the Mediterranean.

Stopovers are planned along the route including in New York, San Francisco, Darwin in Australia, Hong Kong, Singapore, Abu Dhabi and Marseille in southern France.