What compels two American men, at the ages of 51 and 41, to attempt to row across the Atlantic Ocean in a 23-foot home-made boat?

In this honest documentary there is no attempt to veneer over with a gloss of glamour the brutality and soul-searching of John Zeigler, 51, and Tom Mailhot as they attempt the 2001 Atlantic Rowing Challenge using only manpower and oars to cross from the Canary Islands, off Africa, to reach Barbados.

The record time for the crossing is 41 days and John and Tom are optimistic they can break that record and win the race against fellow two-person teams, all in identical boats.

Painted on the side of their vessel the American Star is the slogan that gives the documentary its title 'Row Hard, No Excuses'.

Before setting out from the Canary Islands, the documentary, much of which is in the form of video diary onboard the boat, focuses on some of the other teams preparing for the challenge.

Fewer people have rowed across the Atlantic Ocean than have climbed Mount Everest. The side stories of the other teams at first appear as a distraction to the main focus of the film, but as the documentary moves to the 3,000 mile lonely journey across the ocean the occasional reminder of the state, physical and mental of the other teams, puts John and Tom's story into context.

From the seemingly forever jovial Canary Island team of Pancho and Pedro to the only husband and wife team, which becomes a story in itself, as the husband Andrew Veal, a 6ft 5in international oarsman bails out in the second week uncontrollably spooked by the ravages of the open sea, leaving his 5ft 5in wife Debra to row more than 2,500 miles alone.

There is certainly scope to expand on these other teams and what at first appeared an annoying interruption to the flow of John and Tom's story soon presents a fascinating insight into the trials of being cooked-up in close company with another person, bobbing around in the smallest of boats and months of relentless rowing.

The frightening weight of expectations that parents hold on their offspring is shown by John's lifelong striving, even at 51, to "be enough" to win his father's love and praise. There is an element of parental approval being sought on Tom's side also.

The strains of two friends being forced to live on top of one another, to row non-stop day and night is exposed in disagreements. And the sheer physical punishment beyond anything they had imaged is lain bare as the documentary unfolds brings the men to the end of their odyssey deflated that their boat and their bodies had not performed as they had thought, and questioning what they had achieved.

In equal measure there is soul searching and meditation by others in the transatlantic rowing race. Additional commentary is provided by friends and family of the rowers. And by Tori Murden, the first woman to row solo across an ocean, whose words are amongst the last to be heard as the 87-minute documentary ends and she expresses a hope that John and Tom will eventually fully appreciate what they achieved.

This unglamourised examination of one of the toughest physical endeavours in the world provides thought-provoking moments carried and remembered by the viewer long after the final frame has ended.