Niall Iain Macdonald set off from Cobb's Marina in Norfolk, Virginia in the US on May 23 in a bid to row about 3,400 miles across the North Atlantic to his home in Stornoway on the Isle of Lewis.
However on Monday night his rudder broke in heavy weather and he feared he would have to abandon his NY2SY challenge, as he had been forced to in 2014, when he suffered a back injury days into his first bid to row across the Atlantic.
Describing the wait on his blog, Back on course, he wrote: "After that, I basically went into a meltdown as I thought that I would have to abandon the row, and my boat, again.
"Disbelief, shock, sadness. I managed to get my head together for a while and began packing some dry bags with various things that could be salvaged from the boat.
"I then just sat and waited for the Coastguard to appear."
However, when US Coastguard cutter Diligence arrived on Wednesday the crew told him they should be able to fix the rudder and took him on board, where they carried out repairs in their engineering room.
They then returned him to his boat, Alba, and fixed the rudder back in place.
Mr Macdonald, a Gaelic broadcaster, said the coastguards saved his row and expressed his gratitude to them.
He wrote: "I cannot find the words to express my gratitude to the crew of USCGC Diligence for all they did. I was treated so well onboard and there were never any questions like 'what are you doing out here' or any judgments.
"All they ever asked was 'how can we help?', 'is there anything else that you need?'. A few hours earlier I had resigned myself to the fact that, once again, I would be returning home months earlier than planned and without my boat.
"Now, I am able to continue with my row and that is down to the hard work, ingenuity, persistence and professionalism of the crew of USCG Diligence. Thank you so much."
Mr Macdonald is now continuing his row and hopes to arrive in Stornoway in September.
He is aiming to raise awareness of mental health issues and at least Â£100,000 for Scottish mental health charity SAMH.
The US Coastguard said they were delighted to help.
Lieutenant Commander Brian Chapman, executive officer, said: "The row boat Alba's rudder was giving Mr Macdonald some trouble, so we dropped in to assist.
"He came by and visited with us shortly while the engineers helped with the rudder. The Diligence crew truly enjoyed learning about Mr Macdonald and his journey.
"He was most inspiring.
"Mr Macdonald and the Alba are back under way, next stop Scotland. We are rooting for Niall here too. His courage and tenacity embody the best in what we strive to be."
Donations can be made via Mr Macdonald's JustGiving page at www.justgiving.com/NY2SY.