Anthony Marchand, skipper of Actual Ultim 4, saw his trimaran halted on Monday, November 2nd, about 400 miles off the Breton coast, after the central rudder caught on “an external element,” according to Team Actual. It was his first Route du Rhum, a solo race between Saint-Malo and Pointe-à-Pitre. The boat, which carries extensive electronics, was designed to keep this technology discreet.
Electronics Hidden in the Hold
During a visit to Lorient in late September, the trimaran looked from the outside like a very large carbon sailboat. Three LiDARs, sensors that measure distances using lasers, are partly concealed in fairings, and the optical fiber is integrated into the structure. In the hold, a consumer-grade mini PC manages the LiDARs, one of the few non-redundant elements on board.
The boat has no solar panels. Two wind turbines provide electricity, and a diesel engine is used to leave port or assist a competitor. The mast, installed on June 30, 2026 and built by Lorima, is two meters longer than the old one and allows the shape of the mainsail to be modified via hydraulic rams. The LiDARs, which scan the sail at several heights, have shown that its trim also affects its upper part, according to the team.
All the sensors produce 1,600 different measurements, of which 350 meters of optical fiber monitor structural deformations. The data volume remains modest, 300 to 400 MB per day of sailing, as it is mostly numbers. A Starlink antenna, a satellite communication system, sends this data to the design office. During the Route du Rhum, multihulls are allowed to be routed from shore, unlike monohulls.
An Artificial Intelligence Mostly Ashore
It is in the Lorient hangar that the artificial intelligence really comes into play. The design office, comprising six to eight engineers according to team manager Yves Le Blévec, uses a digital model of the boat, constantly corrected based on feedback from the skipper. The 1,600 measurements are sorted, cross-referenced, and analyzed to identify what matters.
On board, the system closest to AI is the autopilot, from the Exocet range by Pixel sur Mer. It reads its sensors and reacts according to programmed rules. A machine learning step is mentioned: the autopilot would learn from the skipper’s actions. Zoom and infrared cameras at the masthead, meanwhile, are meant to spot obstacles in time.
An Invisible Obstacle at 40 Knots
The trimaran, which had reached peaks of 40 knots during the night, was halted shortly after 7:52 a.m. on Monday, November 2nd. Anthony Marchand writes: “I caught something in the rudder, maybe a mooring line,” while specifying he was only making assumptions. The bolts holding the rudder gave way, and the boat turned around without the skipper being able to steer it.
According to Team Actual, the situation was stabilized in less than an hour, “thanks to Anthony’s great skill and close, immediate coordination with his technical team ashore.” Alone on board, he had to furl his gennaker, a maneuver that took a good half hour. The trimaran then headed for Galway, Ireland, at less than 12 knots, for an initial assessment. On Tuesday, November 3rd, Anthony Marchand officially remained in the race, the decision to restart to be made after the steering system inspection.
