Bonatti Waterproof Jacket

Designed squarely around the needs of mountain runners and fastpackers, this shell fulfills mandatory race kit requirements without burdening your pack. Built around a lightweight 2.5-layer waterproof fabric, it is designed to compress down into its own chest pocket and virtually disappear inside a hydration vest until a ridgeline storm forces your hand.

On the trail, the trim athletic cut prevents annoying fabric flap in high winds, and the elasticated hood stays securely planted over your brow without requiring fiddly cord locks. Mechanical venting in the back aids airflow, which is critical because the 10k-rated membrane will struggle to vent pure vapor during redline climbs. In prolonged, driving rain, the face fabric eventually saturates, and like most ultralight 2.5-layer shells, the inner laminate can feel clammy against bare arms once sweat builds up.

Durability aligns with its running pedigree rather than traditional mountaineering. The gossamer face fabric resists wind and light snagging, but grinding it under heavy multi-day backpack straps or bushwhacking through dense scrub will quickly compromise the membrane. At this tier, it trades the bombproof protection of heavier three-layer hardshells for agility and packable insurance, serving as an exceptional just-in-case shield when speed is your primary defense.