The families of four British sailors who are missing in the Atlantic say they remain hopeful they will be found.
Speaking after a meeting at the Foreign Office, relatives said they felt "very positive" about the search.
Foreign Office minister Hugh Robertson thanked the US Coast Guard "for their significant efforts".
Debris has been spotted near to where the 40ft Cheeki Rafiki disappeared, but the US Coast Guard later said it was not related to the missing yacht.
The Cheeki Rafiki, based in Southampton, was sailing back to the UK from Antigua when it went missing.
The search for the vessel was originally called off on Sunday but resumed on Tuesday.
About 12,000 square miles of ocean have been covered since then, with the search focused on an area some 1,000 miles off Cape Cod, Massachusetts.
'Right behind us'
The four missing crew members are Paul Goslin, 56, from West Camel, Somerset; skipper Andrew Bridge, 22, from Farnham; Steve Warren, 52, from Bridgwater; and 22-year-old James Male, from Romsey.
Graham Male, James's father, said the meeting with Foreign Office officials was "very constructive".
"It really filled the families in with detail," he said. "What we can say is that the UK government and the US Coast Guard are right behind us, which we are so grateful for."
Mr Male said he had been told more resources were heading to the search area and thanked everyone for their support.
He added: "The boys will be positive out there and the families are positive."
Cressida Goslin, Mr Goslin's wife, described the search efforts as "wonderful" and said: "I don't think anyone could be doing anything more than they are."
US Coast Guard Capt Anthony Popiel said of the debris: "During searches at sea, it is not uncommon to find debris or discarded objects.
"Locating smaller items in the ocean is actually an indicator of favourable seas and search conditions. Our search assets have found a variety of debris and trash during their searches.
"The key part is correlating these objects to the search effort. We take reports of debris very seriously and, at this time, no debris or objects reported during this search correlate to the Cheeki Rafiki."
Simon Ridley, skipper of the Gertha 4 yacht which is taking part in the search, said conditions were very good.
He told the BBC: "Visibility is brilliant at the moment. We've got brilliant blue sky and intermittent clouds. We can see for two miles."
Mr Ridley said the sea was "relatively calm", adding: "We couldn't have better conditions."
Foreign Office minister Hugh Robertson said of his meeting with the families: "The UK government remains in constant contact with our US colleagues and I was able to update them on the continuing search.
"I'd like to thank the US Coast Guard for their significant efforts thus far, and to assure everybody that the UK government will continue to do everything possible to try and locate these missing yachtsmen."
The relatives visited the US Embassy later and delivered letters to US President Barack Obama, the US Coast Guard and the US ambassador to express their gratitude for resuming the search.
The families, who took letters of thanks to the prime minister and foreign secretary for their efforts so far, said they hoped people would be able to join the search online using satellite technology.
Mr Warren's partner, Gloria Hamlet, said: "If there are eyes out there looking for them then there's a chance.
"Hopefully today will be the day but we've got to wait and see."
An RAF Hercules has joined the three planes and six ships already deployed to search the area where the sailors are thought to have disappeared. A number of yachts have also joined the search.
The decision to resume the search followed an official request from the UK government. An online petition, set up to urge the US Coast Guard to resume the search, attracted more than 200,000 signatures.
Capt Popiel has said no decision has been taken on when to suspend the search, and pledged that teams would continue to hunt for the Britons as if they were "looking for a member of our own family".