EVENT 901 Open/Male 10 /Over 200m Butterfly - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 1 | Henry WILLERTON | 11 | Boston | 3:38.46 |
| 2 | 3 | Stanley THURLOW | 12 | Lincoln Vulc | 3:35.35 |
| 3 | 6 | Thomas HILLSON | 11 | Grantham | 3:20.96 |
| 4 | 8 | Ben CARLYLE | 14 | Grantham | 3:11.31 |
| 5 | 7 | Samuel NICHOLS | 12 | Grantham | 3:16.19 |
| 6 | 5 | Fabian KOLASA | 13 | Grantham | 3:21.04 |
| 7 | 2 | Luca HALLAM | 12 | Grantham | 3:37.99 |
| Heat Number - 2 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 10 | Robbie DUFF | 13 | Lincoln Vulc | 3:00.88 |
| 2 | 13 | James HUCKLE | 13 | Lincoln Vulc | 2:54.24 |
| 3 | 15 | Christopher WILLERTON | 40 | Boston | 2:46.87 |
| 4 | 17 | Oliver SHEPHERD | 15 | Deepings | 2:44.04 |
| 5 | 16 | Jack BELL | 15 | Deepings | 2:46.51 |
| 6 | 14 | Harry VICKERS | 16 | Lincoln Vulc | 2:53.80 |
| 7 | 11 | Benjamin MORRIS | 15 | Boston | 2:59.16 |
| 8 | 9 | Rian SOUTHWOOD | 14 | Louth | 3:05.37 |
| Heat Number - 3 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 19 | Jack HICKS | 15 | Lincoln Vulc | 2:43.10 |
| 2 | 21 | Zach HOPKINSON | 15 | Grantham | 2:41.27 |
| 3 | 25 | Daniel HEPPLESTONE | 14 | Co Lincoln P | 2:32.02 |
| 4 | 27 | Layton ANNISON-SNOWDEN | 15 | Louth | 2:31.65 |
| 5 | 26 | Aaron SADLER | 14 | South Lincs | 2:31.75 |
| 6 | 22 | William VERE | 15 | South Lincs | 2:39.59 |
| 7 | 20 | James CASH | 14 | Deepings | 2:41.56 |
| 8 | 18 | Matthew TOMPKINSON | 15 | Louth | 2:43.93 |
| Heat Number - 4 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 29 | Daniel DEGNAN | 16 | Grantham | 2:26.89 |
| 2 | 31 | Jacob FISH | 15 | Grantham | 2:24.93 |
| 3 | 33 | Owen HATHWAY | 18 | Grantham | 2:15.00 |
| 4 | 35 | Rico BRINGEMAN | 19 | South Lincs | 2:04.02 |
| 5 | 34 | Oscar GOLDSMITH | 16 | South Lincs | 2:15.00 |
| 6 | 32 | Alex SADLER | 17 | South Lincs | 2:19.10 |
| 7 | 30 | Jacob BRIERS | 16 | Deepings | 2:26.55 |
| 8 | 28 | Ryan NORTON | 17 | Boston | 2:28.14 |