Stefan Hannan, 15 started the meet with an outstanding PB in the 200m backstroke of 2:22.50 - which qualified him for the New Zealand Short Course Championships this year - but then bettered that by making a six-second PB when winning silver in the 100m breaststroke in 1:15.01.
"Hannan made it a double, placing second in the 200m breaststroke in 2:44.63, another substantial PB," said Lowe.
The teenager also had creditable swims in the 50m and 100m freestyle, with 26.81 and 58.69 second times.
In the female events, Jazmin Phillips, 14, showed improvement across all strokes, highlighted by her silver in the 100m breaststroke in 1:22.25, followed by bronze in the 200m at 2:56.22.
Eleishah Hodson, 15, brought home bronze in the 100m backstroke final after a determined swim saw her record a PB by three seconds at 1:12.05.
Other notable performances came from Liam Cox, 15, and Luke Gemmell, 14.
Cox reached seven finals and just missed the bronze medal behind Hannan in the 200m breaststroke event, posting a PB of 2:45.22.
Competing at his first national event, Gemmell swam some outstanding PB times and made his way into finals in the butterfly and medley events, including finishing fourth in the 400m medley with 5:28.27.