EVENT 45 Boy Open 100m Butterfly - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | AaD | Cat | Club | Time |
| 3 | 1 | Kruze Frampton | 11 | | Seagulls SC | 1:37.34 |
| 4 | 3 | Jack Palmer | 12 | | Poole | 1:23.19 |
| 5 | 2 | Lewis McLaughlin | 12 | | Seagulls SC | 1:25.66 |
| Heat Number - 2 |
| Lane | Comp.No. | Name | AaD | Cat | Club | Time |
| 2 | 5 | Monty Tibbatts | 12 | | Bourmth Coll | 1:15.87 |
| 3 | 7 | Zack Sturgess | 15 | S10 | S Bournem'th | 1:14.68 |
| 4 | 9 | Leo Wisbey | 13 | | Poole | 1:12.00 |
| 5 | 8 | Benjamin Jackson | 15 | | Poole | 1:13.55 |
| 6 | 6 | James Gunn | 14 | | West Dorset | 1:15.81 |
| 7 | 4 | Scott Grocott | 13 | | S Bournem'th | 1:22.98 |
| Heat Number - 3 |
| Lane | Comp.No. | Name | AaD | Cat | Club | Time |
| 1 | 11 | Toby Whetstone | 14 | | Poole | 1:11.83 |
| 2 | 13 | Edward Bell | 15 | | Seagulls SC | 1:11.30 |
| 3 | 15 | Xavier West | 16 | | Poole | 1:10.73 |
| 4 | 17 | Frederick Beasley | 15 | | Poole | 1:08.90 |
| 5 | 16 | Cameron Willcocks | 15 | | S Bournem'th | 1:09.37 |
| 6 | 14 | James McNamara | 15 | | Poole | 1:11.25 |
| 7 | 12 | George Emery | 16 | | West Dorset | 1:11.31 |
| 8 | 10 | Mark Talalaykin | 14 | | Poole | 1:11.88 |
| Heat Number - 4 |
| Lane | Comp.No. | Name | AaD | Cat | Club | Time |
| 1 | 19 | Hugo Young | 14 | | S Bournem'th | 1:07.38 |
| 2 | 21 | Harley Taylor | 15 | | Wareham | 1:06.46 |
| 3 | 23 | Felix Merritt | 16 | | Poole | 1:06.11 |
| 4 | 25 | George Gillett | 16 | | Seagulls SC | 1:05.68 |
| 5 | 24 | Freddie Hodgetts | 15 | | Poole | 1:06.08 |
| 6 | 22 | Gabriel Petrov | 16 | | S Bournem'th | 1:06.38 |
| 7 | 20 | Charlie Meek | 16 | | Poole | 1:07.27 |
| 8 | 18 | Elliott Dunnett | 14 | | S Bournem'th | 1:08.74 |
| Heat Number - 5 |
| Lane | Comp.No. | Name | AaD | Cat | Club | Time |
| 1 | 27 | Jamie Workman | 15 | | Bourmth Coll | 1:04.80 |
| 2 | 29 | Alexander Peaty | 18 | | Wareham | 1:03.41 |
| 3 | 31 | Harry Stewart | 18 | | West Dorset | 1:03.18 |
| 4 | 33 | Oliver Jones | 17 | | Poole | 1:02.09 |
| 5 | 32 | Matthew Workman | 18 | | Bourmth Coll | 1:02.63 |
| 6 | 30 | Luca Parkes | 17 | | S Bournem'th | 1:03.40 |
| 7 | 28 | Max Looker | 16 | | Poole | 1:03.42 |
| 8 | 26 | Oliver Deretz | 16 | | Poole | 1:04.90 |
| Heat Number - 6 |
| Lane | Comp.No. | Name | AaD | Cat | Club | Time |
| 1 | 35 | Gabriel Knight | 17 | | S Bournem'th | 1:01.01 |
| 2 | 37 | Lawrence Elliott | 17 | | Seagulls SC | 1:00.48 |
| 3 | 39 | Sonny Chamberlain-Hyde | 19 | | Seagulls SC | 58.89 |
| 4 | 41 | Robbie Hemmings | 18 | | Poole | 57.32 |
| 5 | 40 | Isaac Ellis | 18 | | Seagulls SC | 58.70 |
| 6 | 38 | Alexandru Chiriac | 17 | | Poole | 59.24 |
| 7 | 36 | Luca Sartorius | 15 | | Poole | 1:00.82 |
| 8 | 34 | Max Leigh | 16 | | Blandford | 1:01.04 |