| Event | Time | Meet | Date |
|---|---|---|---|
| 100m Breaststroke | 1:18.76 | 2025 Huronia Region LC Team Challenge | 2025-06-05 |
| 100m Breaststroke | 1:14.28 | 2026 Huronia SC Regional Championships | 2026-02-06 |
| 100m Butterfly | 1:04.80 | 2026 Huronia SC Regional Championships | 2026-02-06 |
| 100m Freestyle | 1:02.69 | 2025 Huronia Region LC Team Challenge | 2025-06-05 |
| 100m Freestyle | 1:00.28 | Otters Devo & Distance Winter Waves | 2026-01-24 |
| 200m Backstroke | 2:21.80 | OSAC Team Challenge Short Course Swim Meet | 2025-11-14 |
| 200m Breaststroke | 2:50.90 | 2025 Huronia Region LC Team Challenge | 2025-06-05 |
| 200m Breaststroke | 2:41.12 | 2026 Huronia SC Regional Championships | 2026-02-06 |
| 200m Butterfly | 2:31.05 | 2025 Alan Swanston Classic | 2025-12-05 |
| 200m Freestyle | 2:16.80 | 2025 Huronia Region LC Team Challenge | 2025-06-05 |
| 200m Freestyle | 2:08.57 | Otters Spooky Splash 2025 | 2025-10-24 |
| 200m IM | 2:22.41 | 2026 Huronia SC Regional Championships | 2026-02-06 |
| 400m Freestyle | 4:38.62 | OSAC Team Challenge Short Course Swim Meet | 2025-11-14 |
| 400m IM | 5:10.01 | OSAC Team Challenge Short Course Swim Meet | 2025-11-14 |
| 50m Backstroke | 31.60 | 2025 Huronia Region LC Team Challenge | 2025-06-05 |
| 50m Breaststroke | 36.13 | 2025 Huronia Region LC Team Challenge | 2025-06-05 |
| 50m Breaststroke | 33.89 | OSAC Team Challenge Short Course Swim Meet | 2025-11-14 |
| 50m Butterfly | 29.71 | 2025 Huronia Region LC Team Challenge | 2025-06-05 |
| 50m Butterfly | 28.54 | 2025 Alan Swanston Classic | 2025-12-05 |
| 50m Freestyle | 28.81 | 2025 Huronia Region LC Team Challenge | 2025-06-05 |
| 50m Freestyle | 27.89 | Otters Devo & Distance Winter Waves | 2026-01-24 |
Mahadana Arachchi, Nethaya's top personal bests include 100m Breaststroke (1:18.76), 100m Breaststroke (1:14.28), 100m Butterfly (1:04.80), 100m Freestyle (1:02.69), 100m Freestyle (1:00.28).
Mahadana Arachchi, Nethaya swims for Orangeville Otters Swim Club.
Mahadana Arachchi, Nethaya has competed in 8 meets.