| Event | Time | Meet | Date |
|---|---|---|---|
| 100m Backstroke | 1:08.22 | 2025 Summer Divisionals - Vancouver & Fraser | 2025-06-27 |
| 100m Breaststroke | 1:05.87 | 2026 BC Winter Provincial Championships | 2026-03-05 |
| 100m Butterfly | 59.62 | BC Winter Divisionals - Vancouver & Fraser | 2026-02-20 |
| 100m Freestyle | 55.68 | VPSC Winter Invitational 2025 | 2025-12-05 |
| 1500m Freestyle | 1:32.65 | OS October Distance Time Trial | 2025-10-11 |
| 200m Backstroke | 2:18.03 | PSW June Jamboree 2025 | 2025-06-07 |
| 200m Freestyle | 2:04.05 | PSW June Jamboree 2025 | 2025-06-07 |
| 200m IM | 2:10.84 | BC Winter Divisionals - Vancouver & Fraser | 2026-02-20 |
| 400m Freestyle | 4:43.08 | OS October Distance Time Trial | 2025-10-11 |
| 50m Backstroke | 28.68 | BC Winter Divisionals - Vancouver & Fraser | 2026-02-20 |
| 50m Breaststroke | 30.35 | VPSC Winter Invitational 2025 | 2025-12-05 |
| 50m Butterfly | 27.25 | VPSC Winter Invitational 2025 | 2025-12-05 |
| 50m Freestyle | 24.96 | BC Winter Divisionals - Vancouver & Fraser | 2026-02-20 |
| 800m Freestyle | 9:36.43 | OS October Distance Time Trial | 2025-10-11 |
Murtha, Declan's top personal bests include 100m Backstroke (1:08.22), 100m Breaststroke (1:05.87), 100m Butterfly (59.62), 100m Freestyle (55.68), 1500m Freestyle (1:32.65).
Murtha, Declan swims for Olympians Swimming.
Murtha, Declan has competed in 10 meets.