The Borough of Waltham Forest Swimming Club (BWFSC) excelled at the British Gas Age Group National Championship, where Phoebe Griffiths won two national titles.
A stunning performance from 13-year-old Griffiths saw the teenager crowned national champion in the 800m freestyle at the championships.
Griffiths swam a well-controlled race to finish in a time of 9.07.70 and claim the win.
She also came out on top in the open water event in a time of 19.12.10, once more emerging as national champion.
In addition to her two wins, Griffiths also managed a personal best time of 4.26.87 to finish in fifth place in the 400m freestyle.
Fourteen-year-old Holly Taylor swam the 100m freestyle in 60.07, finishing a creditable 16th out of 40 girls.
The club’s 4x100m freestyle team, consisting of Griffiths, Taylor, Sonia Hallili and Isabelle Andrews, swam a personal best of 4.09.29 to come 29th out of 40 teams.
The club’s head coach, Mike Bush, said of Waltham Forest’s success in the championships: “This has been one of our best nationals ever and I am extremely proud of all the swimmers.”