A French yachtsman has been found alive and well but trapped inside his upturned racing boat after two rivals in a round-the-world race dashed to the vessel 200 miles off Cape Horn.

There had been fears for Jean Le Cam because he had given no definite sign of life since reporting his capsize by satellite telephone just after midnight.

An an oil tanker and a Chilean coastguard plane spotted his pink 60-foot yacht wallowing in the ocean without part of its keel but were unable to make contact. The heavy seas prevented the tanker from approaching the yacht.

Vicent Riou, a fellow Frenchman in the Vendée Globe race, arrived at 15.00 GMT and called Le Cam. He heard an answer. Le Cam is stuck inside because the escape hatch on the stern has been blocked. A Chilean tugboat with rescue divers is now steaming towards his position and should arrive in the early hours of Wednesday.

"I think this rescue episode will take longer than we thought because of difficult conditions at sea," said Denis Horeau, director of the single-handed, non-stop around-the-world race. "We must be patient."

Le Cam, who was in third place in the French-run race, had been believed to be alive because an emergency beacon was triggered when the tanker drew close to his boat in the mid-morning.

The captain decided that it was too dangerous to send a launch to the rescue, so the operation was left to two nearby skippers Riou and Armel Le Cleac'h, the other skipper who sailed towards Le Cam.

The Open class single-handed yachts are supposed to be self-righting but they can remain over-turned if they lose their keels. Photographs showed that the heavyweight bulb is missing from Le Cam's boat. The craft is equipped with an escape hatch to allow the yachtsman to escape if they remain upside down. Two have been rescued in past races after days inside over-turned hulls.

This year's edition of the "Everest of yachting" has proved one of the toughest in the 20 years of the the four-yearly race which starts and ends in the French Atlantic port of Sables d'Olonne. Only 13 boats are left in the race as the turbulent Southern Ocean has taken a heavy toll on competitors. Last month, an Australian navy frigate rescued Yann Elies, another skipper, two days after he broke a leg and nearly lost his life.

Two rivals sailed alongside his stricken yacht while he awaited rescue. They have since been awarded extra time in the race to compensate for their delay. The last to abandon before Le Cam's capsize was Jonny Malbon of Britain. The only remaining women in the race are Britain's Samantha Davies, in fifth place, and Dee Caffari in eighth.

Michel Desjoyeaux, the race leader, rounded Cape Horn early on Monday 56 days 14 hours and eight minutes after the flotilla left Les Sables d'Olonne on November 9. The first boats are expected back in port in mid February. Le Cam is competing for the second time. He came second in the last edition in 2004-5.