Ultra Marin: Running Between Land and Sea in the Heart of the Gulf of Morbihan

There are mountain races, there are road races, and then there's Ultra Marin. This one-of-a-kind trail takes runners along the coastal paths of the Gulf of Morbihan, one of the most beautiful bays in the world, through a landscape of heathlands, rocky foreshore, wild beaches, and charming villages.

Held every year at the end of June starting from Vannes, the Ultra Marin has become one of the most popular trail events in France over its 20 editions. Across 4 days, day and night, 10,000 runners take the start of one of the 8 races, supported by 1,500 volunteers. The 21st edition will take place from June 24 to 28, 2026.

1. The History of Ultra Marin

The adventure begins in 2005 with the creation of the Ultra Marin Raid Golfe du Morbihan association. The idea was simple yet ambitious: create a trail race that loops around this Breton natural jewel using the hiking paths along the coast.

The success was immediate. The event grew rapidly and organized itself around multiple formats to welcome an ever-wider audience. In 20 editions, the Ultra Marin has established itself as one of the biggest trails in France and a must-have on the trail calendar, just as the UTMB is for mountain racing.

The race is made unique by its landscapes, but also by a feature few trails can claim: at the midpoint of the Grand Raid and Raid, runners cross the mouth of the Gulf of Morbihan by boat, aboard rigid-hull inflatables, for a 15-minute out-of-time parenthesis between Port-Navalo and Locmariaquer.

2. The Gulf of Morbihan: An Exceptional Playground

The Gulf of Morbihan (literally "little sea" in Breton, Mor-Bihan) is a vast inland bay in southern Brittany, dotted with about forty islands and islets. Listed among the most beautiful bays in the world, it offers a unique landscape of indented coastlines, marshes, heathlands, and coastal forests.

The coastal paths encircling the Gulf make up Ultra Marin's playground. You'll find yourself running:

• With feet in the water across the foreshore at low tide
• Alongside oyster farms, a true signature of the Gulf
• Through heather and gorse heathlands
• Through charming villages like Séné, Saint-Armel, Sarzeau, Baden, and Arradon
• Facing the islands: Île-aux-Moines, Île d'Arz, and dozens of islets

The elevation gain is modest compared to mountain trails (1,430 m D+ over 175 km), but don't be fooled: technical trails, sea wind, June heat, and foreshore sections make this a demanding event.

3. The 8 Races

Ultra Marin offers 8 formats, from individual races to relays, night races to Nordic walking. All finish at the port of Vannes.

The Grand Raid — 175 km ⭐

• The flagship race: the full loop around the Gulf of Morbihan
• Distance: 175 km
• Elevation: 1,430 m D+
• Cutoff: 42 hours
• Start: Vannes, June 26 at 7 PM
• ITRA: 5 points | UTMB: 100 Miles Qualifier
• Runners set off from Vannes in the evening for a true journey around the Gulf. At the midpoint, they cross the Gulf's mouth by rigid-hull inflatable between Port-Navalo and Locmariaquer. The fastest complete the loop in about 16 hours.

The Raid — 100 km

• The Grand Raid's little sister, present since the 1st edition in 2005
• Distance: 100 km
• Elevation: 810 m D+
• Cutoff: 20 hours
• Start: Saint-Gildas-de-Rhuys, June 25 at noon
• ITRA: 3 points | UTMB: 100K Qualifier
• Runners discover the Rhuys peninsula's ocean side with its short sharp climbs, never losing sight of the sea. After 30 kilometers, they cross the Gulf's mouth by boat before heading to Vannes.

Le Réveil des Ducs — 70 km 🌙

• THE night race of Ultra Marin (3rd edition in 2026)
• Distance: 70 km
• Elevation: 500 m D+
• Cutoff: 14 hours
• Start: Château de Suscinio (Sarzeau), June 27 at 11 PM
• ITRA: 2 points | UTMB: 50K Qualifier
• The nocturnal event. Immersed in a medieval atmosphere at the foot of the former residence of the Dukes of Brittany, runners set off once night has fallen along a sleeping Gulf of Morbihan. At dawn, they discover the Séné peninsula and its coastal paths before reaching the port of Vannes. A magical experience.

L'Arvor — 56 km

• The gateway to long distances
• Distance: 56 km
• Elevation: 500 m D+
• Cutoff: 12 hours
• Start: Auray, June 27 at 9 AM
• ITRA: 2 points | UTMB: 50K Qualifier
• The most "Morbihan" race of Ultra Marin. Starting from downtown Auray, crossing the Saint-Goustan bridge, then coastal paths along the Auray river. Without nearly ever leaving the coast, you discover the Gulf, its sandy beaches, and its many islands.

La Ronde des Douaniers — 34 km

• The fast and accessible format
• Distance: 34 km
• Elevation: 150 m D+
• Cutoff: 6 hours
• Start: Baden, June 28 at 8 AM
• ITRA: 1 point | UTMB: 20K Qualifier
• The fastest race of Ultra Marin, ideal for discovering the event without sacrificing intensity. A great format for a first trail experience.

La Vénète — 29 km (Nordic Walking)

• One of the longest Nordic walking events in France
• Distance: 29 km
• Elevation: 150 m D+
• Cutoff: 6 hours
• Start: Séné, June 26 at 9 AM
• Starting from Séné, walkers take the Sinagot paths past Pointe du Bill and Port-Anna before reaching La Marle, the river leading to the port of Vannes.

The Grand Relay — 175 km as a Team of Four

• The Gulf loop as a team
• Distance: 175 km (4 runners)
• Start: June 26
• Same course as the Grand Raid, but taking turns as a team of 4. Ideal for experiencing the collective adventure of the Gulf loop.

4. The Grand Raid Route: A 175 km Journey

The Grand Raid route is a true tour of the Gulf following the coastline as closely as possible. Here are the highlights:

Start in Vannes (km 0) — 7 PM

The start is given from the port of Vannes, in the heart of the medieval old town. The atmosphere is electric as 1,500 runners set off in the June evening light.

The Southern Coast of the Gulf

• Through Séné and its salt marshes, a haven for migratory birds
• Crossing through Saint-Armel and its oyster farms
• The Rhuys Peninsula with Sarzeau and the Château de Suscinio
• Port-Navalo at the Gulf's entrance, with views of the Atlantic Ocean

The Boat Crossing — The Magical Moment

At the midpoint, runners board rigid-hull inflatables to cross the mouth of the Gulf of Morbihan between Port-Navalo and Locmariaquer. 15 minutes out of time, by day or night depending on your pace. A moment unique in the trail world.

The Northern Coast of the Gulf

• Locmariaquer and the megalithic site of the Grand Menhir Brisé
• Auray and the port of Saint-Goustan
• Baden and its magnificent coastal path
• Arradon, with its breathtaking views of the islands
• Triumphant return to the port of Vannes

5. Tips for Preparing for Ultra Marin

Specific Training

• Build your endurance: On a 175 km race with little elevation, effort management is paramount. Get used to very long runs (4h+).
• Train on coastal trails: The paths are technical with roots, rocks, narrow passages, and sand. Very different from road running.
• Prepare your feet: Between sand, seawater, and foreshore, your feet will be put to the test. Test your shoes and socks on similar terrain.
• Don't forget the heat: Temperatures can rise in June. Train in warm conditions if possible.

Gear

• Trail shoes: Choose shoes with good drainage and good grip on wet rock.
• Gaiters: Strongly recommended to keep sand out of your shoes.
• Sun protection: Sunscreen, cap, and sunglasses — there's little shade on the course.
• Windbreaker: The sea wind is ever-present and can be biting at night, even in June.

Race Strategy

• Start slow: The trap of flat terrain is going out too fast. Fatigue exacts a heavy toll after 100 km.
• Manage the night: The Grand Raid starts at 7 PM, Le Réveil des Ducs at 11 PM. Managing nighttime fatigue is crucial.
• Plan your aid stations: The checkpoints are well-stocked — this is Brittany after all!
• Enjoy the scenery: Sunrise over the Gulf, the boat crossing, sleeping villages... that's also what Ultra Marin is about.

6. The Atmosphere: Brittany's Trail Festival

What sets Ultra Marin apart from many other races is its festive and welcoming atmosphere. Brittany knows how to throw a party:

• The aid stations are legendary: fresh oysters, galettes-saucisses, caramel butter crêpes, far breton... The 1,500 volunteers treat runners to local specialties.
• The crowd is warm and plentiful, even in the middle of the night in the villages along the route.
• Finishers are welcomed as heroes at the port of Vannes.
• The Ultra Marin Outdoor Festival (new in 2026) brings the start/finish village to life for 4 days.
• No Woman No Trail: The organization is committed to more inclusive trail running with dedicated amenities for women (free hygiene products, reserved spaces, bib refund in case of pregnancy).
• Solidarity Medal: Runners can choose to forgo their finisher's medal, with the organization donating to the Ultra Marin Horizons fund for solidarity and environmental projects.

7. Practical Information (2026 Edition)

Registration

• Registration is full for 2026. A bib exchange is open on Klikego.
• Registration typically opens in autumn for the following June — spots go fast.

2026 Calendar

Getting There

• Vannes is accessible by high-speed train from Paris (2h30), Rennes (1h15), or Nantes (1h30)
• Runner shuttles are provided by the organization to reach the various start points
• Accommodation: Book early! Vannes and its surroundings are packed on race weekend

Shuttles and Options

Runner shuttles are available as an option when registering, along with coaching sessions with Run Motion Coach and the collector edition t-shirt.

8. Why Run Ultra Marin?

If you're still hesitating, here are 5 great reasons to sign up:

1. A unique natural setting: The Gulf of Morbihan is a classified treasure. Running along its coastal paths is like crossing through a living postcard.
2. The boat crossing: Boarding a rigid-hull inflatable mid-race to cross the Gulf's mouth is a moment that only Ultra Marin can offer.
3. An accessible ultra: The modest elevation gain (1,430 m D+ over 175 km) makes it an excellent gateway to ultra-trail.
4. Le Réveil des Ducs, at night: Setting off at 11 PM from a medieval castle to run 70 km through the Breton night is an unforgettable adventure.
5. The Breton atmosphere: Between oysters at aid stations, warm encouragement, and a spirit of mutual aid, the Breton welcome is unmatched.

Ultra Marin takes place every year at the end of June, starting from Vannes (Morbihan, Brittany). More info at ultra-marin.fr.

Further Reading

• UTMB: World Summit of Trail Running
• Trail Running: Complete Guide
• Are Some Races Reserved for Elites?
• How to Gear Up for Running in the Rain