Boucle de Seine Half Marathon 2027
- Next event : Sun, March 21, 2027Date confirmed
The event in a few words
Auguste Renoir painted boaters here, you will sign a finish time 🎨. The Boucle de Seine Half Marathon sets up camp in Chatou, in the Yvelines, a short RER ride from Paris. It is run in the heart of the loop that the Seine draws west of the capital. The race takes place in March, when Île-de-France still hesitates between winter and spring 🌷. March showers like to show up unannounced, between clear spells and light rain. So slip a windbreaker into your bag: this changing light delighted the Impressionists, and it will add charm to your morning too ☁️.
Over 21.097 km, you will set off from the Île des Impressionnistes, a long ribbon of greenery set in the middle of the river 🏝️. The route links four towns in town-to-town fashion: Chatou, Croissy-sur-Seine, Le Pecq and Le Vésinet. On the menu: Seine riverbanks, avenues lined with fine residences and a park-town atmosphere. As for elevation, the counter shows 59 m D+, a profile as smooth as the river on a windless morning 🛶. This fast road race suits record hunters as well as runners discovering the half marathon 🏃.
Launched in 2027, the event relies on a course measured according to the standards of the French Athletics Federation 📏. A label application is in progress. The organizers have taken care of the details: waves split by pace, pacers to set your rhythm and an electronic chip to measure your real time.
The Boucle de Seine Half Marathon also runs for a charitable cause alongside France Cérébrolésion. Since 1986, the association has supported people with brain injuries and their families toward greater autonomy and inclusion 💙. According to them, traumatic brain injury remains the leading cause of disability in France. Clubs, associations and companies have dedicated offers to come and run as a group 🎽.
Once the medal is around your neck, the Maison Fournaise awaits you a stone's throw from the finish. This restaurant-museum is where Auguste Renoir painted Luncheon of the Boating Party 🍷. Twice a year, including once in March, the island also hosts the National Flea Market and Ham Fair, a way to replenish your salt reserves after the effort🍖. In Croissy, the banks of La Grenouillère saw Monet and Renoir set up their easels side by side. In Le Vésinet, the park-town conceived by Alphonse Pallu lends itself to a cool-down jog by the water. Le Pecq holds the memory of the first passenger train to leave Paris, inaugurated in 1837 by Queen Marie-Amélie, which took 25 minutes from Saint-Lazare 🚂. To finish, climb up to the Grande Terrasse of Saint-Germain-en-Laye: you will take in at a glance the whole loop that your legs have just devoured 👀.
Renoir gathered his friends around a boaters' lunch. Here, the menu consists of 21 km, a medal and a big breath of Seine air: dinner is served! 🥇
5 reasons to join this race
The distance you'll all agree on
Half MarathonTOP
- Sunday, March 21, 2027 at 9:00 AM
- Elevation gain : 59mD+
- 21.0975 km
A few more words
The start takes place on the Île des Impressionnistes, in Chatou, right in the middle of the Seine 🚦. You will leave the island via the Chatou bridge for a first loop of about 10.5 km through Chatou, Croissy-sur-Seine, Le Pecq and Le Vésinet. The scenery alternates between riverbanks, residential avenues and beautiful villas, on wide, fast sections. The elevation is limited to 59 mD+ in total, probably concentrated on the access ramps to the bridges 🌉. At the halfway point, you will pass close to the island again to start the second loop 🔁. You will then know every turn, the perfect opportunity to speed up ahead of the final sprint. Back on the Île des Impressionnistes to cross the finish line, a stone's throw from the Maison Fournaise 🏁.
Frequently asked questions (FAQ)
Bib pick-up takes place at the gymnasium of the sports center on the Île des Impressionnistes, in Chatou (78400), upon presentation of an ID and the QR code sent by email on Wednesday, March 17, 2027:
Friday, March 19, 2027 from 2 pm to 7 pm;
Saturday, March 20, 2027 from 10 am to 6 pm.
No bibs are handed out on Sunday, March 21, 2027, race day. Only complete files (license or validated PPS) allow pick-up. A third party can pick up your bib if they present their ID (or a copy) and your QR code. Home delivery of the bib is offered as an option for €13, provided you complete your file before Sunday, March 7, 2027.
The half marathon will start on Sunday, March 21, 2027 at 9 am, on the Île des Impressionnistes, in Chatou. Runners are divided into the following waves:
elite wave (under 1h15) and preferred wave (under 1h30), upon proof of a performance of less than 2 years old obtained in an official race, to be sent to eric@semimarathonboucledeseine.fr;
1h30 to 1h45;
1h45 to 2h;
2h to 2h15;
over 2h15.
You can change waves until Sunday, February 21, 2027. Pacers will be present for target times of 1h30, 1h45 and 2h.
A medical certificate is no longer required. You must provide a valid FFA license (Athlé Compétition, Athlé Entreprise, Athlé Running or Pass’ J’aime courir), a license from a federation recognized by the regulations stating no contraindication to running in competition, or the Parcours Prévention Santé (PPS) certificate. The PPS can be obtained at pps.athle.fr for €5 and is valid for 1 year. The document must be uploaded to your Klikego account no later than 5 days before the race.
The race is open starting from the junior category, with a minimum age of 17 on the day of the event according to the regulations. Minor participants must provide parental authorization when registering.
Prices change depending on the number of registrants:
for the first 500 registrants: €36 for FFA license holders and €39 for non-license holders;
for the next 1,000: €40 for FFA license holders and €43 for non-license holders;
after that: €45 for FFA license holders and €48 for non-license holders.
Several paid options are available:
refund guarantee for €8;
home delivery of the bib for €13;
personalized medal plaque sent after the race for €12;
results by SMS for €1;
T-shirt for €20.
No on-site registration is possible. Bib resale is only authorized through the Klikego bib exchange.
Yes. The regulations provide for a time cut-off around km 10.5, at the start of the second loop, set at 1h15 of race time. The maximum time to complete the course is 2h30 according to the regulations.
According to the regulations, liquid aid stations are provided at km 5, 10 and 15, a solid food station around km 10, as well as a full refreshment station at the finish.
No specific equipment is required. The bib must be worn on the front of the shirt, fastened with 4 pins and fully visible. Headphones, bicycles and wheeled devices are prohibited on the course.
Registration includes:
the bib with a timing chip (Breizh Chrono);
a bottle of water and a solid refreshment at the finish;
a metal medal for every finisher;
access to the free baggage storage.
The T-shirt is offered as an option at the time of registration.
Free baggage storage is set up in the start area, on the Île des Impressionnistes, from 7:30 am to 12 pm. Bags must not exceed 40 cm x 35 cm x 20 cm (backpack size), and it is recommended to drop them off 45 minutes before the start. Toilets are available at the start and at the finish. There are no showers at the finish. 2027 info on changing rooms coming soon.
There are several ways to reach the Île des Impressionnistes:
by RER A, get off at Chatou-Croissy station, then allow about 15 to 20 minutes of walking via avenue de Colmar and the Chatou bridge;
by bus, lines 158, 244, 367, 6427 and 6470 serve the Rue du Port stop, about a 4-minute walk away;
by car, take the A14 or A86 then exit 35a (Chatou), reference GPS address: 3 rue du Bac, 78400 Chatou. Free parking is available under the Chatou bridge.
To join the volunteer team, simply go to the dedicated page on the organizer's website.
The organizer, Sports Concept Organisation, can be reached via the contact page of the website semimarathonboucledeseine.fr or by email:
liza@semimarathonboucledeseine.fr for general questions, refunds and volunteering;
eric@semimarathonboucledeseine.fr for clubs, associations and preferred bibs;
sylvain@semimarathonboucledeseine.fr for companies.
You can check the race rules here
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