"I'm going in there blind and they don't know me, so it's a challenge."
Electric fence and hardware company Gallagher is backing the world record bid. The contenders will head across the sea in Titan, an 11m rowing boat made of aircraft standard lightweight carbons, titanium, nylon and aluminium.
Veteran ocean rower Simon Chalk is the captain.
"It's going to be physically stressful and mentally stressful because you won't get as much sleep as you normally would," said McCowan.
He expected food to be mostly dehydrated sachets. In appalling weather, rowers could retreat to a cabin on the boat.
McCowan's days will be spent rowing for two hours, then two hours off - all day, every day.
Sporadic internet and satellite access were the usual method of contact back home.