The Route du Rhum got underway from St Malo in Brittany this week with near-perfect conditions — bright sunshine, gentle 8-11 knot breezes and huge crowds packed along the shore — but the celebration was dented within hours. Two hours after the start, Violette Dorange's IMOCA Initiatives Coeur collided with Romain Pilliard's 60ft trimaran Use It Again. Both skippers walked away unhurt, though both boats need repairs and are heading to Roscoff.

The incident is a reminder of what makes this race unusual. A field of 115 solo sailors, split across six classes from monster 100ft Ultim trimarans to smaller monohulls, all start on a single line. The classes are sectioned along the line — the biggest boats furthest offshore — but the early stages of the course are still a chaotic free-for-all of boats of wildly different speeds. Video of the collision shows Dorange's IMOCA reaching faster to leeward before sailing into the trimaran; neither skipper managed to avoid contact. Pilliard's boat has a damaged float, a missing hatch and visible hull damage, while Initiatives Coeur took a hit to its starboard foil.

There's plenty of star power in the story, too. Dorange, just 25, has already completed a Vendée Globe and is one of the most popular skippers in French ocean racing — she'd been third early on. Pilliard is a veteran on his third Route du Rhum, sailing a trimaran with serious pedigree: it's the former Kingfisher/B&Q in which Ellen MacArthur set her records, now part of his circular-economy campaign in the Vintage Multi fleet. His team hopes he can rejoin the race after repairs.

Away from the crash, the racing looks tasty. Tom Laperche leads the Ultim fleet on SVR-Lazartigue, just ahead of Armel Le Cléac'h, with the boats hitting speeds over 35 knots. Sam Goodchild leads the IMOCAs on Macif Santé Prévoyance. With building 20-knot north-easterlies forecast, the fleet will run further north than usual — and a critical gybe is expected once the leaders pass the Fastnet Rock, where the wind should swing east. Everyone is chasing the same prize: 3,500 miles across the Atlantic to Guadeloupe in the French Caribbean.

For travellers, the Route du Rhum is worth knowing about even if you never set foot on a boat. The start from St Malo's walled port town is a genuine spectacle — a free, four-yearly festival atmosphere on the Brittany coast — and if you happen to be in Guadeloupe weeks later, the finish line parties in Pointe-à-Pitre are just as lively. Even a collision can't spoil that.