Four Britons are missing at sea after the yacht they were sailing to the UK from a regatta in the Caribbean is feared to have capsized in the mid-Atlantic Ocean.
The crew of the Cheeki Rafiki 40ft performance racer/cruiser yacht ran into difficulties on Thursday while returning from Antigua Sailing Week.
Contact with the four yachtsmen was lost in the early hours of Friday while they were diverting to the Azores.
US and Canadian aircraft and merchant vessels looked for them throughout Friday and Saturday but have now called off the search, according to British yacht training and charter firm Stormforce Coaching.
Stormforce director Doug Innes said: "The yacht Cheeki Rafiki, a Beneteau First 40.7, was on passage from the Caribbean to the UK with a crew of four yachtsmen. On Thursday she started taking on water.
"We were in contact with the skipper and at the time the yacht and crew were keeping the situation stable.
"They had not been able to ascertain where the water ingress was from and were diverting to the Azores.
"Unfortunately we lost contact during the early hours of Friday morning and we believe it is possible the crew abandoned to the life raft.
"Search and Rescue authorities were mobilised and a mixture of Canadian and US aircraft along with merchant vessels searched throughout Friday and Saturday.
"Although the search efforts co-ordinated by Boston were exceptional we are devastated that the search has now been called off so soon.
"Our thoughts are with the four yachtsmen and their families and we hope and pray for them all."
A Foreign Office spokeswoman said: "We are aware of a missing yacht off the East Coast of the USA with four British nationals on board.
"We are in contact with the US Coastguard and have offered consular assistance to the families".
Three of the four crew members were named by a Stormforce spokeswoman as Andrew Bridge, 21, Paul Goslin, 56 and Steve Warren, 52.
They are thought to have been delivering the vessel back after it participated in Antigua Week, regarded as one of the world's top regattas.
All three were described as "very experienced offshore yachtsmen", but only Mr Bridge was being paid by Stormforce for his role on the yacht.
The fourth crew member was named as 23-year-old James Male.
Stormforce, which was acting as the managing agent for the Cheeki Rafiki, is based at Shamrock Quay Marina in Southampton.