The incident occurred about a kilometre offshore from the port of Nyon, in the canton of Vaud, as the 78.5-metre-long paddle steamer headed toward the medieval village of Yvoire, on the south side of the lake.
It collided with the sailboat shortly before noon and 15 minutes before the start of the Luthi 870 sailing regatta organized by SNN, Nyon’s sailing club or “société nautique”, the 24heures newspaper reported.
The youth received injuries to one arm, while another person was injured as the other four occupants were forced to jump off the sailboat, the newspaper reported online.
The force of the collision broke the mast of the sailboat, which may have led to the 15-year-old’s injuries, 24heures said.
Other boats in the area were able to pick up the sailors thrown overboard.
The Simplon is operated by CGN, the Lake Geneva General Navigation Company.
Kathia Mettan, spokeswoman for CGN, said the company’s vessels have priority over pleasure boats, 24heures reported.
“We are shocked and very sorry that there has been an injured person, a youth who was starting his career as a navigator,” Christian Schlappi, vice chairman of the Nyon sailing club is quoted as saying.
Schlappi was not sure exactly what caused the accident but he said he was unaware of another collision involving a CGN boat..
“It is likely that the CGN’s vessel had underestimated the speed of the sailboat while the skipper of (the sailboat) had not precisely seen where the Simplon was because it would have been hidden behind a sail,” he said.
Schlappi said the sailboat’s skipper was the best of the regatta and had plenty of experience.
The sailboat ended up jammed under part of the Simplon’s hull in front of its paddlewheels.
It has been taken to a boat repair yard at Crans-près-Céligny.
The Simplon, a Belle Epoque vessel capable of carrying almost 1,000 passengers, was also slightly damaged although it was able to continue on its way shortly after the accident.