Sumarpo
Grafham Water Swimrun
Grafham Water
Sunday 29th June 2025
We’re excited to be partnering once again with Anglian Water for our 2025 Grafham Water Swimrun —
A stunning venue that offers a perfect blend of trail adventure and open water challenge.
This year’s event features three exciting distances to choose from:
🏃♀️ 5K Fenland Runner Intro Swimrun
🏃♂️ 10K Monkey Sox Sprint Swimrun
🏃♀️ 21K Precision Hydration Half Swimrun
Each course is carefully designed to showcase the very best of Grafham Water.
Expect undulating trails, beautiful woodland tracks, and crystal-clear reservoir swims with easy water entries and exits.
All routes begin by heading out along the scenic north shore, with open water swims across natural bays, and trail runs
winding through reed beds and woodland. The 5K and 10K courses loop back along the shore to finish near the race village,
while the 21K course takes athletes further — through the nature reserve and around the full perimeter of the reservoir.
Whether you're dipping your toe into swimrun for the first time or looking to take on a longer, more adventurous challenge,
Grafham Water Swimrun 2025 has something for everyone.
Don’t miss out, if you haven't entered - ENTER NOW and start your next adventure!
Pricing
5k £35
10k £55
21k solo £105
21K team £205
No extra fees at checkout
Sunday 29th June
- 0700 hrs to 0845 hrs Registration is Open.
- 0815 hrs 21k and 10k Mandatory Race Safety Brief
- 0830 hrs Race Start 21k
- 0835 hrs Race Start 10k
- 0845 hrs 5k Mandatory Race Safety Brief
- 0900 hrs Race Start 5k
- 1030 hrs Prize Giving for 5k and 10k tbc
- 1130 hrs Prize Giving 21k tbc
Our 5k Intro Swimrun race consists of approx.
1.4k of open water swimming and 4km of mixed terrain running. 4 swim sections 5 run sections. Longest swim 550m, longest run 1200m
Our 10k Mild Mustard Sprint Swimrun race consists of approx.
2.9k of open water swimming and 8 km of mixed terrain running. 7 swim sections 8 run sections. Longest swim 620m, longest run 1350m
Our 21k Middling Mustard Half Swimrun race consists of approx
4.5k of open water swimming and 17k of mixed terrain running. 11 swim sections 12 run sections. Longest swim 620m, longest run 6000m
The Courses
5k Intro Solo Swimrun Course
Start time 0900 hrs
Splits
Run 1 1100m
Swim 1 240m
Run 2 700m
Swim 2 450m
Run 3 1200m
Swim 3 550m
Run 4 330m
Swim 4 240m
Run 5 1100m
Course Details
Distance 5.997 km
Ascent/Descent 48 m / 48
Uphill 2.16 km (36.0%)
Downhill 1.89 km (31.5%)
Flat 1.89 km (31.5%)
Steepest Uphill +4.4% (at 5.22 km)
Steepest Downhill -7.8% (at 1.98 km)
Longest Uphill 0.63 km (at 3.06 km)
Longest Downhill 0.81 km (at 3.69 km)
10k Solo Swimrun Course
Start time 0835 hrs
Splits
Run 1 200m
Swim 1 400m.
Run 2 900m
Swim 2 240m
Run 3 1300m
Swim 3 450m
Run 4 1700m
Swim 4 500m
Run 5 1500m
Swim 5 580m
Run 6 900m
Swim 6 550m
Run 7 330m
Swim 7 230m
Run 8
1100m
Course Details
Distance 9.595 km
Ascent/Descent 68 m / 69 m 42 m
Uphill2.97 km (31.0%)
Downhill2.70 km (28.1%)
Flat3.87 km (40.3%)
Steepest Uphill+5.6% (at 0.63 km)
Steepest Downhill-7.8% (at 4.50 km)
Longest Uphill0.99 km (at 4.86 km)
Longest Downhill0.81 km (at 5.85 km)
Aid Station at 6k
Cut off into any water at 1130hrs
21k Solo & Team Course
Start time 0830hrs
Splits
Run 1 200m
Swim 1 400m
Run 2 900m
Swim 2 240m
Run 3 1500m
Swim 3 450m
Run 4 1700m
Swim 4 500m
Run 5 1500m
Swim 5 580m.
Run 6 6000m
Swim 6 250m
Run 7 2300m
Swim 7 300m
Run 8 1300m
Swim 8 10m
Run 9 500m
Swim 9 700m.
Run 10 2300m
Swim 10 400m
Run 11 350m
Course Details
Distance21.192 km
Ascent/Descent 147 m / 148m
Uphill 6.84 km (32.3%)
Downhill 6.21 km (29.3%)
Flat 8.10 km (38.2%)
Steepest Uphill+6.7% (at 8.37 km)
Steepest Downhill-6.7% (at 4.86 km)
Longest Uphill 0.72 km (at 5.49 km)
Longest Downhill 1.53 km (at 16.92 km)
Camping
The closest camp site is
Grafham Water Caravan and Motorhome Site.
Church Rd, Grafham. PE28 0BB
Tel 01480 810264
