Nearly 92 years have elapsed since Captain Charles Bartlett, standing in his pyjamas on the bridge of the biggest vessel in the world, the HMHS Britannic, gave the call to abandon ship.
It was 8.35am on November 21 1916. The four-funnel ocean liner, built to be even larger and safer than the "unsinkable" Titanic, her ill-fated sister, was listing fast. Bartlett knew the ship was doomed, but on this eerily calm morning as it sailed to collect troops wounded in the first world war's Balkans campaign, neither he nor any of his crew could have imagined the speed with which the vessel would go down.
The explosion occurred at 8.12am, sending a giant shudder through the gargantuan vessel, badly damaging its bow as it steamed past the Greek island of Kea. Fifty-five minutes later, the 269-metre (883ft) "wonder ship" lay starboard side down on the seabed.
There the Britannic, which was launched in February 1914 at Belfast, and, the following year, put to use as a wartime hospital ship for the first time, would stay at a depth of 122 metres (400ft), untouched and forgotten, until being discovered by the explorer Jacques Cousteau, in 1975.
Now, the mystery, and controversy that has shrouded this vessel - which sank so quickly compared with the 160 or so minutes taken by the Titanic - could soon be lifted.
There are plans to turn the shipwreck into a spectacular underwater museum. Its location, which until now has been glimpsed only by a handful of divers, will be opened up to tourists. The aim is for the first tours in submersibles to begin next summer.
Wonderfully intact
Simon Mills, a British marine historian who bought the shipwreck from the UK government in 1996 and who organised the underwater project with Greek officials, told the Guardian: "Our plan is to start off with three- or four-seater submersibles. The Titanic lies in the cold waters of the north Atlantic and is rapidly disintegrating because of iron-eating bacteria, in a couple of hundred years there will be very little that is recognisable. But the Britannic is completely different. She lies in warm waters, is very well preserved and wonderfully intact. For so long she has been eclipsed by her older sister but she also has her own story to tell."
Few have firsthand knowledge of the final moments of that story other than the people of Kea, who sped out in fishing boats to rescue the 1,036 doctors, nurses and crew hit by the disaster.
The island's vice-mayor, Giorgos Euyenikos, said: "Everyone here knows about the events of that morning because every family in some way was involved. When the ship went down there was a very loud sound and locals rushed to the highest point of the island to see what was happening.
"My father was a boy when it happened and he remembers his father recalling the howls of people crying out in sheer agony as they met their deaths." But, unlike the huge loss of life on the Titanic, only 30 people on the Britannic perished, partly because the vessel was on an outward journey and not carrying any patients.
But it was the manner of those deaths that has set the Britannic apart. As Bartlett tried to beach the liner after the explosion holed the ship, two lifeboats that had been lowered without his knowledge became sucked into the ship's still churning propellers and were torn apart. All aboard the lifeboats died.
The incident, described in detail by Violet Jessop, an Anglo-Irish nurse who incredibly had also survived the sinking of the Titanic, traumatised those who witnessed it.
Churning propellers
"Not a word, nor a shot was heard, just hundreds of men fleeing into the sea as if from an enemy in pursuit," Jessop wrote in her memoirs, which were published in 1997. "I turned round to see the reason for this exodus, and, to my horror, saw Britannic's huge propellers churning and mincing up everything near them - men, boats and everything were just one ghastly whirl."
Only five of these Britannic victims were ever found.
Mills said that bearing in mind those who had died on board, special care would be taken to preserve the integrity of the wreck.
"This project is not just about tourism but also about education, conservation and marine archaeology," he said.
Mills also hopes to debunk some of the "myths" that have long swirled around the Britannic, including the assertion of conspiracy theorists that in addition to transporting casualties the ship was also carrying military supplies to Allied armies in the Middle East.
Historians have added to the controversy by maintaining that the vessel was torpedoed, despite sonar scan studies conducted as recently as 2003 that reinforced the belief that the liner was brought down by a mine laid by a German U-boat.
"A lot of wartime propaganda endures to this day, not least the German allegation that the Britannic was being misused as a troop transporter when she went down," said Mills. "There is absolutely no evidence to prove this was the case, and we hope that soon these myths will also be laid to rest."
Backstory
The Britannic was launched in 1914, the third of the Olympic-class ocean liners built by the White Star Line at Harland and Wolff's Belfast shipyard. Its size and luxury were such it was originally going to be named the Gigantic. The line redesigned the vessel to correct the defects that had played such a crucial role in the sinking of the Titanic, in 1912. It was announced that the Britannic would sail the Southampton-New York route carrying thousands of immigrants destined for the new world. But the first world war intervened and, requisitioned by the British navy, the Britannic instead began ferrying the wounded from the Gallipoli campaign and other fronts in the Middle East. She was on her sixth outward voyage when disaster struck on November 21 1916 and the vessel sank off Kea, an island near Athens. Controversy has always raged over whether the ship was hit by a mine or torpedo. Some historians believe it was attacked because it was carrying weapons and only dressed up as a hospital ship.
