"It's a really awkward subject for people to talk about, but why?"
Giesen's father Theo said he and his wife were worried about their son setting off on the mission, but were also confident Giesen will make it across the ocean.
"He's training hard and has English rowing adventurer Leven Brown as his mentor," Theo said.
The expert training has come in handy, as Giesen was a rowing rookie when he took on the challenge.
He was living in Croatia working as a skipper, but has since shifted to London to prepare for the marathon trip.
The race kicks off on December 12 and Giesen is hoping the $13,000 he's already raised will increase almost tenfold once he takes to the water.