The daily log of Flying Officer Eric Hartley described their struggle for survival which involved catching food with their underwear and sucking rain-soaked handkerchiefs for water

They created a sail by sewing two of their shirts together using copper wire and also kept morale up by praying twice a day.

In September 1943 , FO Hartley’s crew had sunk a notorious German U-boat that had destroyed 11 Allied ships and who captain was nicknamed Count Dracula .

But in the exchange of fire at just 50 yards, their Halifax bomber was hit, forcing the captain Hartley to abandon the blazing aircraft in the Atlantic, 400 miles south west of Ireland.

Two of the crew were killed and the surviving six men managed to climb into the dingy which had automatically inflated.

But the plane had sunk so quickly the survivors had not had time to retrieve any rations of survival aids.

Their 11 day ordeal saw them battle huge waves and they had to keep awake by splashing freezing water on their faces while using their boots to bail out seawater.

They tried to supplement a meagre ration of a few chunks of soggy chocolate by attempting to use a pair of underpants to cash fish.

“It is the most remarkable collection that tells an extraordinary story of heroism and survival. The logbooks, diary, letters and telegrams cover almost every emotion imaginable.” Simon Nuttall

But all they could scoop up were foul-tasting “slimy, salty” jelly fish that had to be thrown back.

Although they kept up their morale by praying twice a day, two of the crew became so delirious their condition was deemed ‘critical’ and required ‘constant attention’.

The survivors waited close to the crash site for a week, hoping a search party would spot them.

But when nobody came, the men sewed two of their shirts together and used the contraption as a sail to blog them east towards convoy routes.

After four more days, they were spotted by a Plymouth-bound Royal Navy destroyer and given a hero’s reception on board.

Their epic story of survival has come to light after the family of FO Hartley sold the Distinguished Flying Cross he was awarded for more than £3,000.

A black and white picture of the airmen in the dingy at the time they were rescued was also included in the lot.

Simon Nuttall, of Wright Marshall, said: “It is the most remarkable collection that tells an extraordinary story of heroism and survival.

“The logbooks, diary, letters and telegrams cover almost every emotion imaginable.

“One can’t even begin to imagine the feeling of hopelessness and despair the men felt as day after day went by with no sign of rescue and with no food or water.

“That must have given way to sheer relief after they were rescued.”

On board were pilot FO Hartley, co-pilot Captain Roger Mead, navigator Sgt T Bach, engineer Sgt George Robertson, mid-upper gunner Sgt Ken Ladds, wireless operator Sgt A Fox, rear gunner Sgt Robert Triggol and front gunner Sgt Maldwyn Griffiths.