Rescuers are into their third day of searching for a Premier League footballer and a pilot whose plane vanished over the English Channel.
Police said once Thursday morning's searches had finished, a decision would be made whether to continue.
Cardiff City's Argentine striker Emiliano Sala, 28, and pilot David Ibbotson were on the aircraft that disappeared from radar on Monday.
Guernsey Police said no trace of the plane had yet been found.
The force tweeted: "We are commencing a coastal search using the Channel Islands Air Search plane of Burhou, the Casquets, Alderney, the north coast of the Cherbourg Peninsula, north coast of Jersey and then back over Sark."
A spokesman said a search of the island of Burhou had been carried out on foot, but no trace of the plane, Sala or Mr Ibbotson had been found.
But Guernsey harbour master Captain David Barker admitted the chances of finding either man alive had "faded to almost zero".
He added: "As the Channel Islands air searcher said, the survival times for someone in the water is very low, we estimated that at around three hours, the time of survival in a life raft would be longer.
"No-one could be more concerned for these two men's safety than myself... You can be sure that my focus is still on trying to deal with any hope of survival."
The search was suspended on Wednesday night after a second full day of searching and Channel Islands Air Search chief officer John Fitzgerald said "even the most fit person" would only survive for a few hours in the water.
Football agent Mark McKay has confirmed he was involved in the travel arrangements for Sala.
He said: "I can confirm that when Emiliano made myself and his agent Meissa N'Diaye aware that he wished to travel back to Nantes following his medical and signing on Friday, I began to look into arranging a private flight to take him to Nantes on Saturday morning.
"I have been in contact with officials from Cardiff and the player's agent over these difficult past few days and will continue to do so.
"The families of both Emiliano and that of the pilot are utmost in our thoughts and prayers. I knew Emiliano well, he was a wonderful person and I count myself fortunate to have known him."
24th January— Guernsey Police (@GuernseyPolice) January 24, 2019
We are commencing a coastal search using be Channel Islands Air Search plane of Burhou, the Casquets, Alderney, the north coast of the Cherbourg Peninsula, north coast of Jersey and then back over Sark.
Further information released when available
Sala was heading to the Welsh capital after signing for the Bluebirds from French club Nantes in a £15m deal.
The single-engine plane left Nantes, north-west France, at 19:15 on Monday and had been flying at 5,000ft (1,500m) over the Channel Islands when it disappeared off radar near the Casquets lighthouse, near to Alderney.
As part of rescue efforts, police have been looking at satellite images and mobile phone data.
Sala reportedly sent a WhatsApp voice message before the flight. Sounding conversational and jokey, he said he was "so scared" and: "I'm on a plane that seems like it is breaking apart."
His father Horacio Sala said: "As the hours go by it makes me think of the worse. I just want them to find him."
On Wednesday night, Sevilla striker Wissam Ben Yedder dedicated his goal in the 2-0 win over Barcelona in the Copa del Rey quarter-final first leg to Sala.
After scoring, he pulled up his shirt to reveal the message: "To my brother, be strong, E. Sala".
What plane were they on?
The Air Accidents Investigation Branch (AAIB) said a PA-46-310P Malibu aircraft, registered in the United States, had a pilot and one passenger on board when it vanished.
It has begun an investigation, working with counterparts in the US, France and Argentina.
A spokesman said: "We will be gathering all the available evidence to conduct a thorough investigation. However, if the aircraft is not found it is likely to limit the scope of the investigation."
The plane is owned by Southern Aircraft Consultancy Inc Trustee, in Bungay, Suffolk, according to the US Federal Aviation Administration database.
The company told the BBC it was the trustee of the plane but not its ultimate owner.