SERRE-PONÇON SWIM CHALLENGE
10 km & 20 km
Swim the wild heart of the Alps
The adventure begins in
- Friday 3 & Saturday 4 July 2026
- Lac de Serre-Ponçon, Hautes-Alpes, France
The Event - Saturday 4 July 2026
Two distances. One extraordinary lake.
Dive into the Serre-Ponçon Swim Challenge - an open-water event designed for passionate long distance swimmers seeking something truly unique.
Choose your challenge:
Chadenas ➜ Camping du Presqu'île
Chadenas ➜ Baie des Lionnets
With its turquoise waters and alpine backdrop, Serre-Ponçon offers one of the most breathtaking settings for long-distance open-water swimming in Europe.
The Relay — Friday 3 July 2026
A team adventure to start the weekend.
The day before the main event, a friendly relay swim gives small groups the chance to experience the challenge together on a supervised course.
This event is only available as part of a package, perfect for those who want to soak up the full Serre-Ponçon experience before race day.
Limited to 4 teams (2–4 swimmers per team).
Packages
Choose how deep you want to dive into the adventure.
Relay Swim
Full Experience Package:
Only available as a 4 day package with safety boat, coach, chateau accommodation and transport. Possible to combine with solo swim full experience package for small groups of swimmers with different objectives.
Solo 10km or 20km
Swim Only
For swimmers who prefer to organise their own logistics. Includes entry to the 10 km or 20 km swim with kayak and safety kit hire and transfers on race day. Each swimmer must be accompanied by their own kayak support person(s).
Solo 10km or 20km
Hassle Free package
Swim + Accommodation + Transport + More (4 days)
A hassle-free option including event entry, kayak and safety kit hire, accommodation near the lake, acclimatisation swim, interactive immersion experience on the history of the lake, local swim tips, transport to organised activities and swim, and transfers from local train station. Each swimmer must be accompanied by their own kayak support person(s),
Solo 10km or 20km
Full Experience Package
Swim + Accommodation + Transport + Food + Coach + More (5 days)
A complete, all-inclusive stay: acclimatisation swim, professional coaching including private support coach for the event, château accommodation, meals, transfers and transport, interactive immersion experience on the history of the lake and event entry. Ideal for those who want to enjoy the atmosphere, prepare calmly, and live the event to the fullest.
Why Serre-Ponçon?
Because it’s not just a swim - it’s a journey.
Lac de Serre-Ponçon is the largest freshwater reservoir in France, nestled between the Southern Alps and Provence. Its turquoise waters stretch for over 28 km, framed by snow-capped peaks and sun-warmed hillsides — a landscape that feels both wild and peaceful.
What makes Serre-Ponçon truly special is its story.
Created in the late 1950s after the construction of the Serre-Ponçon dam on the Durance River, the lake was built to prevent flooding and provide hydroelectric power. In the process, it transformed an entire valley into one of the most beautiful natural playgrounds in Europe.
The bell tower of the old Saint-Michel chapel, still rising from the water, stands as a reminder of the villages that once lay beneath the surface, and of the human story behind this remarkable place.
With over 80 km of shoreline, glacier-fed waters, and around 300 days of sunshine a year, Serre-Ponçon offers exceptional conditions for open-water swimming: clean, calm, and stunningly scenic.
A limited-capacity event (around 50 swimmers) to preserve the lake and ensure a personal, authentic experience.
Values & Vision
Built on three strong values:
Sport & Nature
promoting open-water swimming as a pure, respectful mountain sport.
Sustainability
raising awareness and supporting the protection of Alpine aquatic ecosystems.
Community
bringing together swimmers, locals, and supporters in a shared celebration of adventure and respect for the environment.
Join the Challenge
Registrations open soon!
Be among the first to receive updates, package details, and early-bird registration links.
Partners & Supporters
The Serre-Ponçon Swim Challenge is made possible thanks to the support of local authorities, businesses, tourism offices, and sustainability partners who share our passion for open-water swimming and Alpine nature.
Become a Partner or Sponsor
Join us in bringing this unique event to life and promoting the values of sport, sustainability, and local heritage.
As a partner, your brand will be visible across our event communications, social media, and on-site banners — reaching a dedicated community of swimmers, outdoor enthusiasts, and visitors from across the world.
We offer several partnership options to suit different goals, from sponsoring safety boats or eco-initiatives to supporting specific event experiences like the relay or finisher celebration.
Get Involved - Become a volunteer
This event wouldn’t be possible without our amazing volunteers!
Whether you’re local to the area or simply love open-water events, there are many ways to help:
- Supporting swimmers and kayakists on the lake
- Assisting with start/finish logistics
- Welcoming participants and spectators
- Helping with catering, check-in, or prize-giving
Volunteers will receive event gear, meals, and an invitation to the post-event celebration.
About the Organisers
The Serre-Ponçon Swim Challenge is organised by a local non-profit association led by a team of swimmers, mountain lovers, and safety professionals — all dedicated to making this dream crossing possible, safely and sustainably.
Sally Guillaume
President of the Association
Founder of Undiscovered Mountains, Sally brings over 20 years of experience organising adventure trips in the Southern French Alps. Passionate about open water swimming, she is the driving force behind the event’s creation and organisation
Chloe Schmitt
Secretary of the Association
Hospital director and open-water enthusiast, Chloé brings structure, precision, and attention to detail to the organisation with a focus on participant welfare and environmental impact.
Philippe Halluin
Treasurer of the Association
Owner of a mountain lodge and passionate long-distance swimmer, Philippe oversees financial management and local logistics coordination
Alex Dupont
Safety Coordinator
Professional lifeguard and rescue expert and open water swimming athlete. Alex has swum the 20km, 30km and 40km on the lake as well as swimming the English Channel. Alex coordinates safety protocols and supervises motorboat operations during the event.
Johan Brochier
Coach and Communications
Swim coach and open-water athlete, Johan contributes to training structure, route planning, and swimmer guidance.