EVENT 123 Boys 16/17 Yrs 100m Breaststroke - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | YoB | Club/Country | Time |
| 1 | 1 | Pierce Greening | 03 | Cumbria | 1:10.32 |
| 2 | 3 | Matthew Rothwell | 02 | Cambs | 1:10.04 |
| 3 | 5 | Louis Metselaar | 02 | Lincolnshire | 1:08.98 |
| 4 | 7 | Max Wass | 03 | Staffs | 1:08.36 |
| 5 | 6 | Dominic McCarthy | 02 | SE Herts | 1:08.46 |
| 6 | 4 | Edward Smith | 03 | Wiltshire | 1:09.35 |
| 7 | 2 | Sam Mead | 02 | Bedfordshire | 1:10.10 |
| Heat Number - 2 |
| Lane | Comp.No. | Name | YoB | Club/Country | Time |
| 0 | 9 | Mackenzie Cannon | 02 | Sussex | 1:07.34 |
| 1 | 11 | Samuel Norton | 02 | Cornwall | 1:07.12 |
| 2 | 13 | Finnian Trehane | 02 | Dorset | 1:06.73 |
| 3 | 15 | Ryan Griffiths | 03 | Warwicks | 1:05.70 |
| 4 | 17 | William Bell | 02 | Leics | 1:05.00 |
| 5 | 16 | Jack Goodwin | 03 | Hampshire | 1:05.35 |
| 6 | 14 | Alexander Cohoon | 02 | Gloucs | 1:06.04 |
| 7 | 12 | Sean Barrett | 02 | Swim Wales W | 1:07.10 |
| 8 | 10 | Freddie Laws | 03 | Norfolk | 1:07.34 |
| 9 | 8 | Chris Vizard | 02 | Worcs | 1:08.31 |