The Army crew will take on 35 teams from around the world in the six-week 3,000-mile race across the North Atlantic in a 27ft boat. The Talisker Whisky Atlantic Challenge, which begins in December, is viewed as the ultimate physical and mental endurance test.

       Rowing in two-hour shifts, Force Atlantic's two-man, two-woman crew will battle sleep deprivation, blisters and salt sores.

       They must race unsupported from La Gomera in the Canaries to the Caribbean beaches of Antigua. The Royal Army Physical Training Corps team of Capt Scott Pollock, 39, from Scotland, Warrant Officer Victoria Blackburn, 39, of Lancs, Sgt Phil Welch, 37, of the Wirral and Sgt Laura Barrigan, 29, of March, Cambs, have trained for 18 months.

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       Scott said: "There is quite simply nowhere to hide. We will eat next to each other, sleep next to each other, wash next to each other."

       An Army source said: "The challenge is a staggering feat of endurance. The isolation and the sheer physical demands will ask questions of them they will never have encountered and probably never will again."