Debris has reportedly been found in the Atlantic Ocean in the area where British yacht Cheeki Rafiki went missing.
The captain of a charter yacht taking part in the search told the BBC that details of what was spotted were passed on to the US Coast Guard.
The 40ft Cheeki Rafiki was sailing back to the UK from an Antigua regatta when it got into trouble and started taking on water last Thursday.
The four-man crew, experienced captain Andrew Bridge, 22, from Farnham in Surrey, and crew members James Male, 23, from Southampton, Steve Warren, 52, from Bridgwater, Somerset, and Paul Goslin, 56, from West Camel, Somerset , have not been seen or heard from since the early hours of Friday.
The US Coast Guard called off the search for the men 48 hours later.
However, the search resumed after a petition signed by politicians, celebrities and leading sailors attracted 200,000 signatures.
Patrick Michel, skipper of the Malisi, volunteering in the search for the missing yacht, said: "We are currently just in the north part of the search area, our third night out here.
“We did see during this night a few little (pieces of) debris which I have reported to the US Coast Guard with the times and positions, so there is a little bit of light at the end of the tunnel."
Kay Coombes, the sister of Mr Warren, welcomed the reports that debris had been spotted.
"I think they've got a bit more of a clue now so hopefully the coastguard can plot that and get the ships to that area, so fingers crossed they can start searching there."
She said the families of the missing sailors were still clinging on to hope, and thanked Mr Michel for taking the time to search and the coastguard for redoubling its efforts.
"They are still out there, there's more resources being put into it, so we're still hopeful at this point," she said.
She added: "We have got to stay positive. We are still hopeful, we are clinging on to that. We are just keeping going. It is exhausting now, this has been going on for days.”