14-year-old Nathalie Hull of Kerikeri was just beaten for first in the female short course, finishing 21 seconds behind Auckland's Helen Turner in 47:43.
Thea Hodge and Leia Weeds from Kerikeri were the top team racing in the short course division, winning in 48:34 in a top effort.
Meanwhile Kurt Coetzee, Charlie Bacon and Levi Cohen (Whangarei) took out the open team swim division in 1:25:21. They were followed by fellow Whangarei unit David Gurnell, David Bowers and Brett Hill in 1:33.10.
The ASB Northland Secondary Schools Sports Association Triathlon was highlighted by many competitors from the 2017 edition returning to try better their previous efforts.
Diego Florez-Diaz (Kerikeri High School) and Jorja Swain (Whangarei Girls High School) won their respective Under 19 individual events in impressively run races.
Greg Hamlet (Huanui College) and Nathalie Hull (Springback School) showcased their abilities to win the Under 16 individual events.
In the junior events, Luka Clark (Huanui College) and Bree Monaghan (Whangarei Girls High School), took out their divisions.
Kerikeri High School student Jamie Doubleday and Kaitaia Intermediate's Glennis Walters showed their huge potential with wins in the two sub-junior divisions.