EVENT 103 Open/Male 100m Backstroke - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | YoB | Club | Time |
| 2 | 1 | Mason JONES | 15 | Weymouth | 1:46.32 |
| 3 | 3 | Finlay BOOTH | 14 | S Bournem'th | 1:45.49 |
| 4 | 2 | Franco HOWLETT | 15 | West Dorset | 1:45.81 |
| Heat Number - 2 |
| Lane | Comp.No. | Name | YoB | Club | Time |
| 1 | 5 | Dylan JORDAN | 14 | Weymouth | 1:41.62 |
| 2 | 7 | Stanley WEIGHELL | 15 | Seagulls SC | 1:37.29 |
| 3 | 9 | Harry MORGAN | 13 | S Bournem'th | 1:32.37 |
| 4 | 8 | Luan ISUFI | 15 | Poole | 1:36.41 |
| 5 | 6 | Fergus STANNING | 15 | Poole | 1:40.06 |
| 6 | 4 | Charlie SHORT | 12 | Wareham | 1:43.88 |
| Heat Number - 3 |
| Lane | Comp.No. | Name | YoB | Club | Time |
| 1 | 11 | Maxwell BLAKE-EVENDEN | 13 | Weymouth | 1:29.73 |
| 2 | 13 | Tyler DOUGLAS | 11 | Blandford | 1:28.93 |
| 3 | 15 | Zachary FLINT | 11 | Seagulls SC | 1:25.01 |
| 4 | 14 | Ethan WANG | 11 | S Bournem'th | 1:27.11 |
| 5 | 12 | Oscar MACHTYLSKI | 15 | Poole | 1:29.29 |
| 6 | 10 | Ralph VEARNCOMBE | 14 | Poole | 1:30.77 |
| Heat Number - 4 |
| Lane | Comp.No. | Name | YoB | Club | Time |
| 1 | 17 | James NEESAM | 08 | Poole | 1:15.93 |
| 2 | 19 | Miron WOZNIAK | 09 | Blandford | 1:13.41 |
| 3 | 21 | Daniel HUSSEY | 07 | Bridport Bar | 1:06.30 |
| 4 | 20 | Aris ROMAN | 09 | Wareham | 1:08.89 |
| 5 | 18 | Dylan HANGER | 11 | Weymouth | 1:14.39 |
| 6 | 16 | Benjamin CRUMPLER | 11 | S Bournem'th | 1:17.09 |