EVENT 302 Open/Male 10 /Over 400m Freestyle - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 2 | 2 | Elliot GLEAVE | 11 | Grantham | 6:23.62 |
| 3 | 4 | Luca HALLAM | 12 | Grantham | 5:55.48 |
| 4 | 6 | Dan PALMER | 11 | Co Lincoln P | 5:42.69 |
| 5 | 5 | Zachary WILSON | 12 | Lincoln Vulc | 5:49.03 |
| 6 | 3 | Thomas HILLSON | 11 | Grantham | 6:18.29 |
| 7 | 1 | Henry WILLERTON | 11 | Boston | 6:30.21 |
| Heat Number - 2 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 9 | Oliver WILKINSON | 12 | Lincoln Vulc | 5:21.05 |
| 2 | 11 | Oliver GARNER | 14 | Co Lincoln P | 5:11.16 |
| 3 | 13 | Charlie WARD | 14 | South Lincs | 5:07.16 |
| 4 | 15 | Jacob HEGG | 14 | Lincoln Vulc | 5:04.13 |
| 5 | 14 | Ben CARLYLE | 14 | Grantham | 5:05.39 |
| 6 | 12 | James HUCKLE | 13 | Lincoln Vulc | 5:10.44 |
| 7 | 10 | Francesco MONACO | 12 | South Lincs | 5:12.81 |
| 8 | 8 | Henry MASON-SMITH | 13 | Louth | 5:24.04 |
| Heat Number - 3 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 17 | Charlie BISBY | 13 | South Lincs | 4:57.30 |
| 2 | 19 | William KITE | 15 | Louth | 4:54.36 |
| 3 | 21 | Harry VICKERS | 16 | Lincoln Vulc | 4:49.43 |
| 4 | 23 | William TAYLOR | 16 | Louth | 4:47.48 |
| 5 | 22 | Matthew TOMPKINSON | 15 | Louth | 4:48.00 |
| 6 | 20 | Luke DAYBELL | 15 | Grantham | 4:50.32 |
| 7 | 18 | James CASH | 14 | Deepings | 4:54.65 |
| 8 | 16 | James THOMAS | 14 | Gainsborough | 4:59.39 |
| Heat Number - 4 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 25 | Oliver SEALEY | 16 | Louth | 4:47.00 |
| 2 | 27 | Jacob FISH | 15 | Grantham | 4:44.49 |
| 3 | 29 | Archie FRENCH | 15 | Lincoln Vulc | 4:43.00 |
| 4 | 31 | Matteo MONACO | 15 | South Lincs | 4:37.59 |
| 5 | 30 | Jacob BRIERS | 16 | Deepings | 4:40.99 |
| 6 | 28 | Daniel HEPPLESTONE | 14 | Co Lincoln P | 4:44.40 |
| 7 | 26 | William VERE | 15 | South Lincs | 4:45.97 |
| 8 | 24 | Layton ANNISON-SNOWDEN | 15 | Louth | 4:47.06 |
| Heat Number - 5 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 33 | Zach HOPKINSON | 15 | Grantham | 4:31.76 |
| 2 | 35 | Jensen HYLTON | 16 | Co Lincoln P | 4:26.14 |
| 3 | 38 | Alex SADLER | 17 | South Lincs | 4:21.70 |
| 4 | 40 | Oscar GOLDSMITH | 16 | South Lincs | 4:19.45 |
| 5 | 39 | Owen HATHWAY | 18 | Grantham | 4:20.79 |
| 6 | 36 | Joshua CLARKE | 16 | Grantham | 4:24.58 |
| 7 | 34 | Ryan NORTON | 17 | Boston | 4:29.52 |
| 8 | 32 | Morgan FARRAR | 15 | Co Lincoln P | 4:33.75 |