Hounslow's Alex Garnett helped Middlesex to its highest-ever finish at the Inter County Championships at Sheffield last weekend.
London 2012 Olympics hopeful Garnett won gold in both the boys 16/17 medley team and mixed 6x50m freestyle team.
Middlesex came third on 473 points, behind Lancashire and Northumberland & Durham.
Ashford trip George Wilson, Ella Kirby and Hayley Nicholson all contributed too, with Kirby and Nicholson coming third in the girls 16:17 medley and George teaming up with Garnett for gold in the 6x50m freestyle.
All four are members of Staines Swimming Club.