Ecosol II will take volunteers around Loch Lomond in the summer

A series of trial cruises will run throughout the summer to test the vessel, called Ecosol II, on the loch.

The national park wants people of all ages to take part and volunteers can learn about Loch Lomond on a PDA.

A spokeswoman described the boat, which can hold 12 passengers and three crew, as a "floating classroom".

Ecosol II will take passengers on a journey across the loch and around islands.

It is practically silent when running and generates no emissions.

'Unique opportunity'

Tim Edwards, of Loch Lomond and The Trossachs National Park, said: "Testing the benefits and performance of a passenger vessel, run on renewable energy, will be a first for Scotland.

"Hopefully the technology will become the norm in the future rather than the exception."

He added: "This is a unique opportunity for people to get involved with something new and exciting while also getting out and enjoying Loch Lomond."

The national park authority is looking for a more fitting name for the boat.

It will run a competition with local schools.