Tommaso D’Orsogna, Kat Downie, Sally Foster, Rhys Mainstone and Simon Huitenga competed in pool and river events against swimmers from China, South Africa, Japan and Brazil.
Huitenga and UWA Uniswim member Mainstone finished second and third in the 10km Swim the Swan on Sunday.
London Olympian Jarrod Poort won the event ” his first national 10km title.
The top three placed swimmers have now improved their chances of selection for the 2014 Pan Pacific Championships on the Gold Coast in August.
In the pool, former Bayswater resident Sally Hunter won the women’s 100m breaststroke.
Dalkeith resident and former Christ Church Grammar School student D’Orsogna won the mixed 4x100m freestyle relay with sisters Cate and Bronte Campbell and James Magnussen in a world record time of 3:23.29.
Westside Christ Church Aquatic Swimming Club member Kat Downie finished third in the Para Sport 200m individual medley.
The Aussie Stingers dominated in the water polo.
They beat China 15-4 and London Olympic gold medallists Croatia 12-9.