An operation is under way to parachute medical help to four sailors who were injured when a large wave crashed onto their yacht during a round-the-world race.
Three British crew members and one Australian were hurt on board the vessel, which is currently 400 miles off the California coast in the Pacific Ocean.
They suffered a range of injuries - including suspected broken ribs - when a wave hit the boat in storm conditions yesterday, sweeping away its steering wheel and mount and some of its communications equipment.
The boat, the Geraldton Western Australia, is one of 10 UK registered 68-foot yachts competing in the Clipper Round The World Yacht Race, which takes place once every two years.
Race organisers Clipper Ventures said the injured crew include Jane Hitchens, a 50-year-old doctor from Kent, who has four suspected broken ribs, and Mark Burkes, 37, from Worcestershire, who has suffered a back injury.
The others were named as Nik Brbora, a 28-year-old software engineer living in London, who has possible pelvic sprain, and 62-year-old Max Wilson, from Queensland, Australia, who has two suspected cracked or broken ribs.
The rest of the 18-strong crew are said to be uninjured but shaken by the incident and those who are medically-trained have treated the four injured crew members.
Paramedics are flying from San Jose, California and preparing to parachute towards the boat and provide medical assistance, the US coast guard said.
The yacht is proceeding towards Oakland, San Francisco Bay, under secondary steering and is expected to reach land within two or three days.
Meanwhile, a container ship, which could pick up the injured people, has been diverted and is expected to reach the yacht within 14 hours.
A spokesman for the US coast guard said: "The parajumpers will assess the injuries. If they need to be taken off the boat we will work around that. The boat would need to be about 200 miles from the shore before a helicopter can reach them.
"The weather conditions are still pretty rough, but it's dying down."
Race Director Joff Bailey said: "We are naturally concerned at the recent incident on Geraldton Western Australia and are in close contact with the skipper, UK Maritime & Coastguard at Falmouth and the US coast guard.
"The safety of all Clipper Race crew is extremely important to us. Our skippers are highly experienced and several crew members on board have medical training."
He said a "deep depression" hit the fleet with winds gusting over 60 knots.
"First reports described the yacht being caught by a large wave. We will issue more details as soon as we have them," he added.
The 40,000-mile race, which features predominantly amateur crews, began on July 31 in Southampton and will finish there in July this year.
Crews began the current leg, which covers 6,000 miles from China to California, in early March.
The US Coast Guard later said medical supplies had been dropped on to the yacht, but poor weather conditions meant the paramedics were unable to jump out of the aircraft.
Explaining the revised plan, coast guard spokesman Levi Read said: "The coast guard rescue co-ordination centre diverted the coast guard cutter Bertholf, and that cutter is making its way towards the vessel.
"The coast guard also launched a long-range helicopter to rendezvous with the Bertholf. Once it's in range the helicopter will be able to take off from the ship and fly to the vessel.
"They will then lower an emergency medical technician from the helicopter on to the boat.
"He will assess the injuries, treat them and if necessary evacuate the injured people and take them aboard the helicopter to the nearest medical resource."
Waves near the yacht are reported to be between 9ft and 15ft, and wind speeds are between 20 and 30mph, he said.
Mr Read added: "It's certainly dangerous out there. But that kind of weather is normal for this time of year especially for the storms we've been having here in California."