Knaggs, who turned 60 just before they set off, added that he hoped he had the “strength of character” to cross the finish line.
Dubbed the World’s Toughest Row, it is expected each team will complete more than 1.5 million strokes over the course of the journey.
Larking said the pair “did not have the greatest of starts”.
“We had 40ft (12m) swells bearing down on us – but on day 31, the state of the sea is better”, he added.
He and Knagg, who are both solicitors, have spent the days and nights talking about their family and friends and planning what they will have for lunch at their favourite restaurant in Harrogate when they get back.
The duo trained six times a week for nearly nine months before setting off, spending nearly 200 hours rowing on the North Sea to gain essential experience in unpredictable waters.
Larking said: “We understood it would be very tough for the first seven days, which it was, while we got into a routine.
“Then you make progress and lose sight of land then you’re in the open Atlantic.”