EVENT 504 Open/Male 10 /Over 100m Butterfly - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | AaD | Cat | Club | Time |
| 3 | 1 | Derrin BROCKLEBANK | 11 | | Grantham | 1:36.42 |
| 4 | 3 | Damir IVANOVS | 10 | | Boston | |
| 5 | 2 | Thomas VERE | 11 | | South Lincs | 1:44.12 |
| Heat Number - 2 |
| Lane | Comp.No. | Name | AaD | Cat | Club | Time |
| 1 | 5 | Henry DOLAN | 12 | | Grantham | 1:38.20 |
| 2 | 7 | Malin FYSON | 12 | | South Lincs | 1:31.81 |
| 3 | 9 | Henry WILLERTON | 12 | | Skegness | 1:30.47 |
| 4 | 11 | Ryan BARGH | 13 | | Co Lincoln P | 1:24.65 |
| 5 | 10 | Jimmin BAO | 12 | | Grantham | 1:28.53 |
| 6 | 8 | George LEONARD | 13 | | Grantham | 1:28.44 |
| 7 | 6 | M PARAPIJONAVICIUS | 12 | | Grantham | 1:29.66 |
| 8 | 4 | Freddie HIRST | 11 | | Grantham | 1:46.66 |
| Heat Number - 3 |
| Lane | Comp.No. | Name | AaD | Cat | Club | Time |
| 1 | 13 | Leo BARNETT | 13 | | Grantham | 1:23.19 |
| 2 | 15 | Dan PALMER | 12 | | Co Lincoln P | 1:21.04 |
| 3 | 17 | Toby EDMONDSON | 11 | | Grantham | 1:22.66 |
| 4 | 19 | Albert HAILE | 13 | | Louth | 1:32.25 |
| 5 | 18 | Fabian KOLASA | 14 | | Grantham | |
| 6 | 16 | Cole COOPER | 13 | | Co Lincoln P | 1:17.90 |
| 7 | 14 | Joshua KIM | 13 | | Grantham | 1:33.47 |
| 8 | 12 | Freddie PRICE | 13 | | Louth | 1:27.03 |
| Heat Number - 4 |
| Lane | Comp.No. | Name | AaD | Cat | Club | Time |
| 1 | 22 | Dominic MCLAUGHLIN | 14 | | Louth | 1:25.13 |
| 2 | 24 | Yu Ching CHEUNG | 14 | | Grantham | 1:18.65 |
| 3 | 26 | Thomas HILLSON | 12 | | Grantham | 1:19.46 |
| 4 | 28 | Ethan HUNTER | 15 | | Lincoln Vulc | 1:14.30 |
| 5 | 27 | Lucas GOODWIN | 14 | | Lincoln Vulc | |
| 6 | 25 | Oliver WILKINSON | 13 | | Lincoln Vulc | 1:18.43 |
| 7 | 23 | Finley WEST | 14 | | Co Lincoln P | 1:17.94 |
| 8 | 20 | Patrick ADEJUWON | 14 | | South Lincs | 1:20.30 |
| Heat Number - 5 |
| Lane | Comp.No. | Name | AaD | Cat | Club | Time |
| 1 | 30 | Cezmi MERMUTLU | 14 | | Louth | 1:17.84 |
| 2 | 32 | Morgan GRIFFIN | 15 | | South Lincs | |
| 3 | 34 | Francesco MONACO | 13 | | South Lincs | 1:19.44 |
| 4 | 36 | Joshua GILL | 22 | S14 | Gainsborough | |
| 5 | 35 | Kieron TOMS | 15 | | Deepings | 1:12.64 |
| 6 | 33 | James THOMAS | 15 | | Gainsborough | 1:13.81 |
| 7 | 31 | Jack HATCH | 15 | | Gainsborough | |
| 8 | 29 | Jacob GIFFORD | 15 | | Louth | 1:14.38 |
| Heat Number - 6 |
| Lane | Comp.No. | Name | AaD | Cat | Club | Time |
| 1 | 38 | Rian SOUTHWOOD | 15 | | Louth | 1:11.97 |
| 2 | 40 | Archie FRENCH | 16 | | Lincoln Vulc | 1:09.53 |
| 3 | 42 | Henry MASON-SMITH | 14 | | Louth | 1:13.41 |
| 4 | 44 | Harry VICKERS | 17 | | Lincoln Vulc | |
| 5 | 43 | James CASH | 15 | | Deepings | 1:06.77 |
| 6 | 41 | Matthew TOMPKINSON | 16 | | Louth | |
| 7 | 39 | Robbie DUFF | 14 | | Lincoln Vulc | 1:13.24 |
| 8 | 37 | James HUCKLE | 14 | | Lincoln Vulc | 1:13.32 |
| Heat Number - 7 |
| Lane | Comp.No. | Name | AaD | Cat | Club | Time |
| 1 | 46 | Oliver GARNER | 15 | | Co Lincoln P | 1:07.03 |
| 2 | 49 | Chris WILLERTON | 41 | | Skegness | |
| 3 | 51 | Oliver SHEPHERD | 16 | | Deepings | 1:03.86 |
| 4 | 53 | Oliver SEALEY | 17 | | Louth | |
| 5 | 52 | Jake ADAMS | 18 | | Louth | |
| 6 | 50 | Benjamin DERBY | 17 | | Lincoln Vulc | |
| 7 | 48 | Kieran LUCY | 15 | | South Lincs | 1:08.31 |
| 8 | 45 | Oliver JONES | 16 | | Lincoln Vulc | 1:10.15 |
| Heat Number - 8 |
| Lane | Comp.No. | Name | AaD | Cat | Club | Time |
| 1 | 58 | Leon BAILEY | 19 | | Louth | |
| 2 | 64 | Jacob BRIERS | 17 | | Deepings | 1:03.23 |
| 3 | 70 | Luke BLANCHARD | 24 | | South Lincs | 1:01.55 |
| 4 | 76 | James DOBNEY | 21 | | Grantham | 1:00.17 |
| 5 | 73 | Owen HATHWAY | 19 | | Grantham | 1:01.56 |
| 6 | 67 | Jack HUGHES | 18 | | Lincoln Vulc | |
| 7 | 61 | Daniel DEGNAN | 17 | | Grantham | |
| 8 | 55 | Alex MANLEY | 33 | | Lincoln Vulc | 1:03.26 |
| Heat Number - 9 |
| Lane | Comp.No. | Name | AaD | Cat | Club | Time |
| 1 | 59 | Daniel HEPPLESTONE | 15 | | Co Lincoln P | 1:08.22 |
| 2 | 65 | Jacob FISH | 16 | | Grantham | 1:09.21 |
| 3 | 71 | Bradley HOLLAND | 17 | | South Lincs | 1:01.29 |
| 4 | 77 | Gareth COCKS | 36 | | Co Lincoln P | 59.73 |
| 5 | 74 | Oscar GOLDSMITH | 17 | | South Lincs | 1:00.62 |
| 6 | 68 | Ryan NORTON | 18 | | Boston | |
| 7 | 62 | Ben CARLYLE | 15 | | Grantham | 1:06.55 |
| 8 | 56 | Layton ANNISON-SNOWDEN | 16 | | Louth | 1:05.27 |
| Heat Number - 10 |
| Lane | Comp.No. | Name | AaD | Cat | Club | Time |
| 1 | 60 | Jack ZERAVICA | 17 | | Grantham | |
| 2 | 66 | Stuart HAMER | 50 | | Co Lincoln P | |
| 3 | 72 | Alex SADLER | 18 | | South Lincs | 1:02.42 |
| 4 | 78 | Joseph PARNELL | 18 | | Co Lincoln P | 59.63 |
| 5 | 75 | Joshua CLARKE | 17 | | Grantham | |
| 6 | 69 | Lucas NEWBOULT | 16 | | Lincoln Vulc | 1:03.35 |
| 7 | 63 | Morgan FARRAR | 16 | | Co Lincoln P | 1:04.31 |
| 8 | 57 | Zach HOPKINSON | 16 | | Grantham | 1:05.08 |