Dorking, United Kingdom · Saturday, June 20, 2026
Fixed Distance 100K
Hydra 75 Mile Ultra
Race completed
121 km Distance
not publishedn/a Climbing
6.1 est Grit · Hardcore
Calculated from 121 km alone — the organiser has not published an elevation profile. Read 6.1 as a floor, not a verdict.
What the course asks
Time limit 30 hours
14:53 min/km average. Generous. Walkable throughout for most of the field. Climbing is unpublished, so this pace is a ceiling on the effort, not a measure of it. Among the most forgiving 100K cut-offs we track. Measured against 208 races of the same distance. Cut-off calculator →
Typical conditions, June
Daytime high 20°C
Night low 11°C
Rainfall Mostly dry
Daylight 16 h 35 m of light
Regional 2001-2020 average for June — NASA POWER, grid elevation 51 m. Not a forecast.
The Aid Station
Course-specific beta from the community
With road terrain, choose a shoe with moderate cushioning for optimal performance.
For 100km+ efforts, prioritize real food at aid stations to prevent palate fatigue.
Gear for this race
Chosen for 121 km of road.
- Trail Running Shoes121 km of road — cushioning that is still there in the last quarter.
- Race NutritionPast 121 km the palate quits before the legs do — carry more than one flavour.
- Hydration VestsFlask capacity for 121 km, without the bounce.
- HeadlampsA 30 h limit puts you out there after dark.
- AccessoriesChafe and blisters end more 121 km races than fitness does.
Course Notes
1mi loop (flat).
Similar races
Other 100K road ultras, closest in distance first.