The Australian Navy is trying to rescue a British man who sustained serious head injuries while rowing across the Indian Ocean.
Mike Noel-Smith, 45, has drifted in and out of consciousness since he suffered concussion, according to his rowing partner, Rob Abernethy.
Neurologists have recommended that Mr Noel-Smith be removed "as a matter of great urgency" but rescuers are not expected to reach them until tomorrow afternoon.
The men's boat was battered by 25ft waves during storms at the weekend which ripped off its rudder, safety rail and stabilising device.
Now organisers hope Mr Noel-Smith's condition will not deteriorate before rescuers from the Australian navy frigate HMS Newcastle can reach him.
The men, both former Army officers, had hoped to raise £250,000 for meningitis research, and to beat the 64-day record for rowing the 4,400 nautical mile journey from Carnarvon, western Australia, to Reunion Island in the Indian Ocean. But the journey, which began in April, has been blighted by problems.
First the men's water purifying equipment failed, leaving them with severely restricted water rations, and then they were hit by storms 1,500 miles off the west coast of Australia.
Mr Abernethy wrote in an e-mail: "Over the past 72 hours we have suffered physical damage to our bodies and structural damage to the boat to the extent that it is unwise and reckless to continue. Mike's head and brain are in a bad way and he has also broken his nose and damaged his eye and needs medical attention asap to ensure that there are no serious cranial complications.
"He knocked himself out whilst adjusting the rudder on Saturday. Happily he was wearing a harness or he would not be lying next to me now.
"We have gone through the worst storm imaginable since then, which has compounded Mike's condition and damaged the boat in key areas. To top it all off we rolled the boat about 12 hours ago and remained 'turtle' for two minutes."Reuse content