Sailing: This race is an unparalleled test of stamina, resilience, skill and courage

It's exhilarating, it's frightening, in turn noisy and then serenely gliding – sailing the sort of giant catamaran in which Ellen MacArthur is chasing the Jules Verne Trophy is one of the longest adrenalin rushes in the world.

Cyclists on the Tour de France take less than half the number of days and sleep in civilised luxury every night, pampered by support teams, as are drivers on the Dakar Rally.

But the 14 crew on Kingfisher 2 have to be their own support team. They have only the prospect of pushing, pushing and pushing again, or failing, and concepts such as a marathon, which lasts only two and a half hours, are inadequate for the 60 days or more in which they drive themselves non-stop in an attempt to break the round-the-world record.

Push themselves too hard and they will make mistakes that could threaten not just their own lives, but their colleagues'.

Push the boat too hard and every kind of calamity from breakage to capsizing awaits, consigning the project to failure and the crew to injury – or death. Push too little and even one minute outside the record is failure.

Fear and frustration are part of the daily diet. Fear because the boat will be on the edge in extreme conditions. When Sir Peter Blake and Sir Robin Knox-Johnston took the record in the catamaran Enza, they did so trying to slow down in gales that threatened to hurl the boat out of control.

Frustration because, even with the most clever weather gurus and satellite information, they can run out of wind at times and be left becalmed.

The key lies in the smooth running of a team that works round the clock in shifts, foreseeing the minor problems that can so quickly develop into crises, and in having people who can fix them swiftly and effectively. And in fitting in with mother nature.

The hard bit of going first south and then back north in the Atlantic is making sure that you do not end up becalmed. The hard bit of careering around Antarcticais making sure that you do not capsize and that you avoid semi-submerged icebergs called growlers.

The task for MacArthur will be to lead her crew through the known weather traps and then play the frontal systems in a part of the globe where there is little shipping, no hope of quick rescue and an endless freezing, soaking assault on mind and body.