Video report by ITV Meridian's Mary Stanley
Hampshire soldier Jack Jarvis sets off tomorrow to attempt something no one has done before - rowing solo from mainland Europe to mainland North America.
The journey is around 4,500 nautical miles and he will be at sea alone for 100 days, rowing almost 50 miles each day.
Jack is raising money for the charity Brainstrust in memory of his grandfather who died of a brain tumour in 2007. He has even remortgaged his flat to help fund the journey.
He starts in Portugal, heading past the Canary Islands and Dominican Republic with the challenge finishing near Miami.
Jack has packed all his supplies. He will eat freeze dried meals and nutritional bars - something he's used to in his military career.
He will burn 8,000 calories a day and lose a stone in weight during the row. He will battle sleep deprivation, salt sores and loneliness.
His family will be in Miami to meet him at the end of the voyage.