Atlantic'Trail - Pornic begins in the dark at 4 AM from Place du 8 Mai 1945 in Rezé. Headlamps are required as the Atlantic coast is still hours away. The primary event is an 80 km trail run from Rezé to Pornic. The series also includes an 80 km relay for two to four runners, a corporate relay, a 36 km run from Sainte-Pazanne to Pornic, a 15 km run from Les Moutiers-en-Retz to Pornic, and a non-timed 10 km Gourmet Hike.
The course starts with approximately 20 kilometers of runnable terrain with minimal elevation gain, reaching the first aid station near Saint-Aignan-Grandlieu at 24 km. The middle section becomes more challenging with hills before Sainte-Pazanne at 40 km. It then transitions to a more consistent 20 km stretch leading to the final aid station in Les Moutiers-en-Retz. From this point, the course directs toward the ocean for the final 10 km into Pornic. This event recreates an old local night hike-trail that guided participants from Rezé towards the sunrise on the coast, finishing at Pornic's port. Erik Clavery, a world trail champion and GR34 record holder, is the event's patron.