The boat was originally named Ecosol II by its makers

The B�ta Gr�ine - boat of the sun - will ferry passengers to the remote island of Inchcailloch.

Access on the island has also been improved with a floating pontoon, new paths, a new rangers station and better facilities for wheelchair users.

Deputy Environment Minister Rhona Brankin paid tribute to the work.

A competition was organised by the national park authority to name the new boat and the winning idea was put forward by eight-year-old Lee Dickson, from Balloch.

Lee is due to travel with Ms Brankin to the island at the southern end of the loch on Tuesday for the official naming ceremony and an inspection of environmentally-friendly developments.

'Groundbreaking technologies'

The German-built boat - originally named Ecosol II - runs on batteries charged by solar panels and is said to be extremely quiet. It has room for 12 passengers and is suitable for people in wheelchairs.

Ms Brankin welcomed the developments, which also include new portable audio guides for visitors.

She said: "It's fitting that during National Parks Week, this solar boat shows that National Parks are at the forefront of developing and using groundbreaking technologies.

"National Parks are trying out new ideas and developing sustainable and environmentally-friendly solutions to the challenges we face. The solar boat is just one of many examples.

"The boat also makes the National Park more accessible by providing disabled access and audio-visual guides to give visitors greater knowledge of the environment, natural heritage and work of the National Park."