Rescue crews searching for missing yacht skipper Ona Unwin admit the chances of finding the woman alive are slim.
The wreckage of the 65-year-old's vessel, the Seagair, was discovered yesterday afternoon near Sennen Cove, west Cornwall, three days after Mrs Unwin was last seen.
Her husband, Carol, yesterday denied his wife was an inexperienced sailor, though fears had been raised locally that Mrs Unwin - who is also known by her middle name, Mary - may have ignored warnings about her own capabilities as a sailor, as well as dismissing weather forecasts which predicted difficult sailing conditions.
Crews are expected to resume the search for the missing woman from around 7.30am.
A Falmouth Coastguard spokesman said: "It is approaching 24 hours since the wreckage of the vessel, believed to be the Seagair, was first discovered. For someone to have survived overnight would be something close to a miracle.
"Mrs Unwin is still a missing person."
Mrs Unwin was the sole person onboard when she left Mousehole in Cornwall on Saturday evening. She had been due to arrive at Bideford in Devon last night, having sailed the bottom of the Cornish coastline before heading north, but relatives became anxious when she failed to show up.
Yesterday coastguards and the police confirmed the wreckage of a vessel found near Sennen was the Seagair, which had been bought last week by Mrs Unwin.
Jerry Hobkirk, owner of Falmouth Yacht Brokers, said he would not have let Ms Unwin sail had he known she would have ignored his pleas not to set off until the weather had subsided. He also said Ms Unwin was advised to embark on a sailing refresher course before taking to the water - something the missing woman also appears to have ignored.
Mr Hobkirk said the 130-mile journey from Mousehole to Bideford would have tested even experienced sailors, let alone in difficult conditions.
He added: "I was amazed when I found out that she had set sail. If I had known, we would have stopped her.
"There were strong winds and rough seas on a piece of coast that has very few escape routes. If you get into difficulties there aren't very many ports to play your 'get out of jail' card with."
Helicopter crews from RNAS Culdrose were also called to help with the search and rescue mission.
Mrs Unwin's husband, Carol, last night denied his wife was an inexperienced sailor.
He told BBC Spotlight: "Before she embarked on the trip she had an expert sailor with her, just to brush up on what she knew.
"He and she were confident about the whole exercise."