More than £220,000 has been raised to fund a private search for missing Cardiff City footballer Emiliano Sala.
The search for Argentine Sala, 28, and 59-year-old pilot David Ibbotson was called off on Thursday.
Their plane disappeared, from radar as they flew over the English Channel on their way to Cardiff on Monday night.
A former Guernsey harbourmaster said the search was “like looking for a needle in a haystack, when you don’t even know where the haystack is”.
Argentina’s president Mauricio Macri has joined calls by Sala’s family for the search to resume
Footballers including Manchester City’s Ilkay Gundogan are among 2,448 people who have contributed to donations for the private search on a GoFundMe page.
Other contributors include Nantes manager Vahid Halilhodzic, Leicester City winger Demarai Gray, Paris Saint-Germain midfielder Adrien Rabiot and Bayern Munich’s Corentin Tolisso.
Organisers of the page, Paris-based football agency Sport Cover, hope to raise a total of €300,000 (£260,000).
Sport Cover’s website lists Sala as a client.
Meanwhile, a petition launched in France to have the search resumed has now gathered more than 80,000 signatures.
Sala’s sister Romina has also said she is “convinced Emiliano and the pilot are alive somewhere in the channel”.
“We’re asking please don’t stop with this effort,” she said, during a visit to Cardiff.
Among those joining calls for the search to continue are Barcelona forward Lionel Messi .
Three planes and five helicopters racked up 80 hours combined flying time looking for the plane, working alongside two lifeboats and other passing ships.
Guernsey’s harbourmaster Captain David Barker has said the decision to call to call off the search was a “difficult” one, but the chances of survival were “extremely remote” and he was “absolutely confident” no more could have been done.
Peter Gill, the island’s former harbour master, said: “It’s like looking for a needle in a haystack when you don’t even know where the haystack is.
“You don’t know which road it’s in, you don’t know which parish it’s in, you don’t even know which county it’s in.”
He added that the sea off Alderney, where the plane lost contact, was anywhere between 50m (164m) to 140m (460ft) deep, with currents measuring up to five knots (6mph).
“It’s very cold and it’s also quite challenging in terms of currents and they are very, very seldom slack. The actual chance of getting down and finding something is very, very difficult indeed,” he said.
But diver Richard Keen, who often looks for shipwrecks in the Channel Islands said he thought there was a “fairly good chance of finding the aircraft”.
“All other aircraft which have ditched around Guernsey were found very quickly by crab pot fishermen. When they’re lifting their pots, they drag their pots across the seabed, they tangle in the aircraft,” he said.
“There’s about a 50% chance of finding it in the next three months.”
The Air Accidents Investigation Branch has begun an investigation which will look at “all operational aspects,” including licensing and flight plans.
The Piper PA-46 Malibu disappeared over the English Channel with Cardiff City’s new signing and Mr Ibbotson on board.
Mr Ibbotson of Crowle, Lincolnshire, held a private pilot’s licence and passed a medical exam as recently as November, according to Federal Aviation Administration records.
Sala signed for the Bluebirds from Nantes on Saturday and was flying back to Wales from Nantes when the plane disappeared from radar.
At 19:15 GMT, Mr Ibbotson made a request to descend before losing contact with Jersey air traffic control.