Mandatory Gear for the UTMB: The Complete List
Written by Victor Michel — history enthusiast and passionate alpinist based in Chamonix. Published July 12, 2026 · Updated August 6, 2026
Mandatory gear must be carried from start to finish, under penalty — race marshals can check it at any time. Here is the list with the exact numeric specifications.
Key takeaways
- Waterproof jacket: 10,000 Schmerber minimum required (20,000 recommended), RET < 13
- 2 headlamps each with a backup power source, 200 lumens recommended
- Survival blanket: 1.40 m × 2 m minimum
- Water reserve: 1 L minimum, 1.5 L recommended on the UTMB/TDS/CCC
Why these precise requirements?
Schmerber — a unit that measures the maximum pressure, in mm of water column, a fabric withstands before letting water through — defined by textile industrialist Charles-Édouard Schmerber and standardised under ISO 811 / EN 20811. In driving rain, the pressure exerted on a garment reaches 1,300 to 2,000 Schmerber: the UTMB's regulatory threshold of 10,000 therefore offers a wide margin, and 20,000 even more.
RET — a standardised index (ISO 11092) that measures a fabric's resistance to venting the water vapour produced by sweat, in m²·Pa/W — the lower the value, the more breathable the fabric. The threshold recommended by the UTMB (RET < 13) corresponds to 'good' breathability, sufficient for most outdoor activities, but not the top-performing tier (RET < 6).
Each specification addresses an identified high-mountain risk: hypothermia in prolonged bad weather (jacket, warm layer, survival blanket), night navigation on a course partly run after dark (headlamps), dehydration on long stretches without aid stations (water reserve). These are not arbitrary constraints: the rules are adjusted after each edition based on incidents observed on the course.
| Item | Specification |
|---|---|
| Waterproof jacket | 10,000 Schmerber minimum (20,000 recommended), RET < 13, sealed seams, integrated hood |
| Waterproof overtrousers | Mandatory |
| 2nd warm layer | Long-sleeve 180 g minimum, or 1st layer 110 g + water-repellent windbreaker |
| Trail bag or vest | Worn for the entire race |
| Water reserve | 1 L minimum, sealed and resealable containers (1.5 L recommended on UTMB/TDS/CCC) |
| Headlamps | 2 lamps, each with a backup power source, 200 lumens recommended |
| Survival blanket | 1.40 m × 2 m minimum |
| Self-adhesive elastic bandage | 100 cm × 6 cm minimum |
| Warm hat or neck gaiter | Mandatory |
| Warm, waterproof gloves | Mandatory |
| Personal cup | 15 cl minimum |
Meeting the regulatory figures doesn't guarantee passing the check: on the ground, the judgment of the check official or race marshal outweighs simple conformity with the stated specifications, since there's no way to instrumentally test every garment at the checkpoint.
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FAQ
What is the minimum waterproofing for the mandatory UTMB jacket?
10,000 Schmerber minimum required, with a recommended RET under 13, sealed seams and an integrated hood. In practice, most runners aim for 20,000 Schmerber for reliable protection in degraded high-mountain conditions. French brands such as Cimalp offer trail jackets at this level — their Storm Pro model is rated at 20,000 Schmerber and 80,000 g/m²/24h breathability, with a 3-layer Ultrashell® membrane.
How many headlamps are mandatory at the UTMB?
Two, each with its own backup power source. 200 lumens are recommended. For a rechargeable lamp, an external battery of at least 5,000 mAh is advised to cover the distance.
What is the minimum amount of water you must carry at the UTMB?
1 liter minimum in sealed, resealable containers, 1.5 liters recommended on the UTMB, the TDS and the CCC given the distance between aid stations.
What are the minimum dimensions of the mandatory survival blanket?
1.40 m × 2 m minimum. This is systematically checked by race marshals, as is the self-adhesive elastic bandage (100 cm × 6 cm minimum).
Is the mandatory gear the same for all UTMB races?
The base is the same (waterproof jacket, warm layer, survival blanket, headlamps, water reserve), but the recommended water quantities and some items vary by race distance — check the official list for your specific race before the start.