CROWDS gathered on Portland to mark the beginning of an epic expedition, which will replicate one of the greatest rescue missions in history.

Dignitaries, adventurers and members of the public looked on as a special boat was lowered into the water at Portland Marina yesterday.

It is an exact replica of James Caird, the boat skippered by Sir Ernest Shackleton when he undertook a voyage across the Southern Ocean in 1916.

The vessel, named after his granddaughter The Honourable Alexandra Shackleton, will be crewed by a team of adventurers who hope to re-enact his mission.

Tim Jarvis, an Antarctic explorer and environmental scientist who will be leading the adventure, said: “I am very honoured to be here as part of a wonderful crew to launch the Alexandra Shackleton.

“She is an exact replica of the James Caird, the boat Alexandra’s grandfather sailed from the Antarctic to South Georgia to raise the alarm and save his men.

“I was honoured when Alexandra asked me to be a part of this.”

Mr Jarvis said in the current economic struggle, it was important to remember what Shackleton stood for.

He said: “The time is right for us to remember Shackleton’s message, which was the importance of getting a group of people to all pull together, looking to achieve a goal seemingly impossible.”

In January 2013 the team will attempt to re-enact Shackleton’s voyage from Elephant Island to South Georgia in a trip dubbed The Shackleton Epic.

After the 800-mile crossing, three men will traverse South Georgia in an attempt to reach the abandoned whaling station of Stromness, where Shackleton raised the alarm during his ill-fated Imperial Trans-Antarctic Expedition.

The replica boat was built in Lowestoft but was launched at Portland Marina because operators Dean & Reddyhoff have strong links with the Navy and the Fleet Air Arm.

Weymouth and Portland Mayor Graham Winter said: “It’s great this has been able to take place here.

“It honours the fact that Portland is an important part of sailing life, as well as the ongoing legacy of the sailing academy, especially with the Olympic Games this year.

“It is an honour to be here and to feel a part of something historic.”

The crowd was treated to three sea shanties from Island Voices, who composed the songs themselves.

David Wright, whose Royal Marine son James was killed in Afghanistan last year, was at the launch in honour of his great uncle Hubert Hudson – navigator on Shackleton’s mission.

Mr Wright, 52, said: “It’s a very proud day today, not only to honour my great uncle, but also because of our family’s connection with the Marines.”

The Hon Mrs Shackleton said: “It is an absolute pleasure to be here today and to see such hard work celebrated.”