EVENT 301 Men MC 400m Freestyle - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | YoB | Club | Time |
| 3 | 1 | Zachary WILSON | 12 | Lincoln Vulc | 6:19.78 |
| 4 | 3 | James HUCKLE | 11 | Lincoln Vulc | 5:42.40 |
| 5 | 2 | Dan PALMER | 13 | Co Lincoln P | 6:15.67 |
| Heat Number - 2 |
| Lane | Comp.No. | Name | YoB | Club | Time |
| 2 | 5 | James CASH | 10 | Deepings | 5:14.94 |
| 3 | 7 | Charlie BISBY | 11 | South Lincs | 5:08.80 |
| 4 | 9 | Morgan FARRAR | 09 | Co Lincoln P | 4:54.41 |
| 5 | 8 | Zach HOPKINSON | 09 | Grantham | 4:55.92 |
| 6 | 6 | Daniel HEPPLESTONE | 10 | Lincoln Vulc | 5:12.00 |
| 7 | 4 | Francesco MONACO | 12 | South Lincs | 5:36.50 |
| Heat Number - 3 |
| Lane | Comp.No. | Name | YoB | Club | Time |
| 1 | 11 | Kieran NG | 10 | South Lincs | 4:50.04 |
| 2 | 13 | Jake ADAMS | 07 | Louth | 4:48.76 |
| 3 | 15 | Finnley DANBY | 06 | Boston | 4:44.19 |
| 4 | 17 | Jacob FISH | 09 | Grantham | 4:42.73 |
| 5 | 16 | Jacob BRIERS | 08 | Deepings | 4:43.43 |
| 6 | 14 | Evan NOORPURI | 07 | Lincoln Vulc | 4:48.34 |
| 7 | 12 | Jensen HYLTON | 08 | Co Lincoln P | 4:49.42 |
| 8 | 10 | William TAYLOR | 08 | Louth | 4:52.44 |
| Heat Number - 4 |
| Lane | Comp.No. | Name | YoB | Club | Time |
| 1 | 19 | Joshua CLARKE | 08 | Grantham | 4:36.95 |
| 2 | 21 | Oliver SORRELL | 07 | South Lincs | 4:27.28 |
| 3 | 23 | Owen HATHWAY | 06 | Grantham | 4:21.20 |
| 4 | 25 | Alex SADLER | 07 | South Lincs | 4:15.30 |
| 5 | 24 | Alfie BISBY | 07 | South Lincs | 4:16.00 |
| 6 | 22 | Oscar GOLDSMITH | 08 | South Lincs | 4:21.50 |
| 7 | 20 | Ryan NORTON | 07 | Boston | 4:34.97 |
| 8 | 18 | Matteo MONACO | 09 | South Lincs | 4:41.30 |