Wanaka's Benjamin Silipo led the success with two medals, bagging a gold and a silver.
He swam 4min 40.45sec to win the 14 boys 400m individual medley, while his 1min 59.22sec secured silver in the 200m freestyle.
Jessica Scott also claimed a silver in her first event.
The Neptune swimmer finished the 17-18 women's 50m butterfly in 28.44sec to finish just behind North Shore's Gina Galloway.
She had Otago's best result in the open finals as well, finishing eighth in the A final.
Kiwi's Madison Wills also secured her first medal of the week, a bronze in the 15 girls 100m breaststroke.
Her 1min 12.97sec swim left her comfortably in the medals.
The meeting continued yesterday with the age-grade races in the morning and the open finals in the evening.
It goes until Saturday.
