A swimathon will see scouts attempt to complete an incredible 1,324 lengths of the pool to raise funds for their hut redevelopment project.
The 7th Feltham sea scouts group will be joined by beavers, cubs, leaders, friends and family to help complete the 20.6-mile challenge - equivalent to the smallest width of the English Channel - on Sunday (May 17).
The swimathon will take place at the pool at Hanworth Air Park Leisure Centre and youngsters are calling on the community to help by coming along to cheer them on the from the sidelines and donate towards the cause.
They hope to raise £2,000 towards rebuilding their scout hut.
Past members of the scout groups and their families have also signed up to help complete the challenge.
Each beaver, cub and scout has also been issued with a sponsorship form and a fundraising page has been set up for online donations.
The event will take place between 9am and 5pm. To join email firstname.lastname@example.org and to donate click here.