| Placing | Athlete | Team | Preliminaries |
|---|---|---|---|
| 1 | Sam Johnstone | Ashburton College | 1:00.70q |
| 2 | Joshua Westland | Timaru Boys' High School | 1:03.80q |
| 3 | Todd Houston | Mt Hutt College | 1:04.90q |
| 4 | Nathaniel Wilson | Mountainview High School | 1:10.80q |
| -- | Shayle Baldwin | Waitaki Boys' High School | NT |
| -- | Tom Pavletich | Roncalli College | NT |
| Placing | Athlete | Team | Preliminaries |
|---|---|---|---|
| 1 | Blair Grant | Waitaki Boys' High School | 1:02.00q |
| 2 | Bradley Ryan | Timaru Boys' High School | 1:02.40q |
| 3 | Josh Schreiber | Geraldine High School | 1:03.40q |
| 4 | Tolu Obafemi | Ashburton College | 1:04.00q |
| 5 | Ethan Winn | Mackenzie College | 1:11.50 |
| -- | Daniel Dorgan | Roncalli College | NT |
| -- | Anthony Leach | Opihi College | NT |
| Placing | Athlete | Team | Finals |
|---|---|---|---|
| 1 | Blair Grant | Waitaki Boys' High School | 55.70 |
| 2 | Todd Houston | Mt Hutt College | 58.70 |
| 3 | Sam Johnstone | Ashburton College | 1:01.80 |
| 4 | Joshua Westland | Timaru Boys' High School | 1:02.80 |
| 5 | Tolu Obafemi | Ashburton College | 1:02.90 |
| -- | Bradley Ryan | Timaru Boys' High School | NT |
| -- | Josh Schreiber | Geraldine High School | NT |
| -- | Nathaniel Wilson | Mountainview High School | NT |