Three British crew members and one Australian were hurt on board the vessel, which is 400 miles off the coast of California, US.
They suffered a range of injuries – including suspected broken ribs – when a wave hit the boat in storm conditions in the Pacific on Saturday, 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 20.7-metre (68ft) yachts competing in the Clipper round-the-world yacht race, which takes place every two years.
The race organisers, Clipper Ventures, said the injured crew included 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 a 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.
An attempt was made at around 6pm local time to parachute medical help to the sailors but it was abandoned after poor weather conditions meant paramedics were unable to jump out of the aircraft.
A helicopter carrying medical supplies will be sent to help as around 8am local time on Sunday from a coastguard ship. Subject to their medical condition, the injured crew will be taken off the yacht.
Explaining the revised plan, the US coastguard spokesman Levi Read said: "The coastguard rescue co-ordination centre diverted the coastguard cutter Bertholf, and that cutter is making its way towards the vessel.
"The coastguard 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 2.7 and 4.6 metres (9ft and 15ft), and wind speeds are between 20mph and 30mph, he said.
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."
The yacht is heading towards Oakland, California, under secondary steering and is expected to reach land within two or three days.
The race director Jonathan Bailey said: "We are naturally concerned at the recent incident on Geraldton Western Australia and are in close contact with the skipper, UK Maritime and Coastguard at Falmouth and the US coastguard.
"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."
