Recovering drug addicts will help to restore the Skylark IX, which was used for cruises at the beauty spot for 33 years before falling into disrepair near Balloch in 2010.
It was one of more than 700 “Dunkirk Little Ships” involved in Operation Dynamo, which saw 338,226 soldiers rescued from the shores of France on a hastily-assembled fleet over eight days.
Now it is to be restored to its former glory after a charitable trust set up to secure the future of the vessel won a pledge of more than £400,000 from the Heritage Lottery Fund.
The 50 ft long vessel was originally built in Dorset as a passenger cruiser in 1927 and acted as a shallow water minesweeper in Poole during the Second World War before being called up in 1940 to assist stranded Allied troops at Dunkirk.
After the war, the Skylark moved north, via Morecambe and Burntisland, to Loch Lomond, where cruise operator John Sweeney offered Dunkirk veterans a free trip once a year.
However, it was left lying in a sunken state at Balloch for several years until the Royal Navy helped raised the Skylark in 2013, before she was transferred to the Scottish Maritime Museum in Dumbarton.
Recovering drug addicts are helping to restore the vessel, which will eventually make short trips along the Clyde to and from the museum.
A team of community volunteers will be recruited to help recount the history of the boat, which will also be made available for schools, visual art and music events in future.
Anne Dyer, chair of the Skylark Recovery Trust, said: “For three years now, we’ve stood together in our modern day rescue mission to pay honour to our Dunkirk Little Ship.
“We have the local community behind us both young and old and today with the great news of initial approval from Heritage Lottery we’re moving forward for sure.
“We’re pleased to say that recovery through recovery for both the people and the boat is within our grasp and her story will live on for generations to come."
Meanwhile part of a former prisoner of war camp in Perthshire is to be turned into self-catering accommodation after community leaders in Comrie won a pledge of £638,000 to transform 11 Second World War Nissen Huts.