The story of her sinking is one of the dramas of World War 2.
Now the story is augmented by a sensational tale of salvage.
From The Telegraph -- where the writer seems addicted to the word "boat"...
British salvage boat recovers treasure from wreck of SS City of Cairo
British salvage boat breaks world undersea salvage record by recovering bulk of 100-ton treasure from wreck of British wartime steamboat SS City of Cairo at depth of 17,000 feet – some 4,500 feet deeper than the Titanic.
The SS City of Cairo was sunk by a German submarine 480 miles south of St. Helena on November 4 1942 en route from Bombay to England with 100 tons of silver coins on board housed in 2,000 rectangular black boxes.
The U-68 struck the slow-moving steamship with one torpedo but waited a further 20 minutes before inflicting the coup de grace, thus allowing all but six of the ship's 302 passengers and crew to escape on to lifeboats.
The German captain, Karl-Friedrich Merten, then approached the lifeboats and famously told the survivors in perfect English: "Goodnight, sorry for sinking you."
It took three weeks before the bulk of the crew were rescued, by which time 104 people on board the lifeboats had died.
The ship's vast treasure in silver rupees belonging to the UK Treasury was thought lost forever.
However, a team led by Briton John Kingsford, a search and salvage veteran, managed to track down the elusive cargo using a powerful survey and salvage vessel equipped with sonar and robotics.
Under contract to the UK Ministry of Transport, underwater company Deep Ocean Search (DOS), was authorised to recover several tens of tons of the coins.
"Our research came up with the usual contradictions between the positions given by the submarine and that from the ship's officers," said the company.
Miraculously, the team, which included 20 French oceanographers, finally pinpointed the stricken craft "broken in two and buried deep in the sea floor silt" at a depth of 5,150 metres (17,000 feet).
Recovery at this depth is a "world record", DOS said. By comparison, the Titanic rests at a depth of 3,800m, or 12,500 feet.
Maeva Onda, among the oceanographers on board the ship SV John Lethbridge, said the search submarine met with success on its first dive. "After two hours of underwater descent, the robot transmitted the first images of the wreck. It was incredible," she told Le Figaro.
Its identify was confirmed when the robot uncovered coins stamped with the Crown. "The emotion was tangible on the boat and when we brought the first coins up, it was even more intense," she said.
However, it was not plain sailing from there, as the extreme depth caused "serious difficulties" in recovering the bulk of the treasure, the team said. "The combination of pressure, temperature, repeated dives at this depth and other issues resulted in multiple breakdowns of systems such as we had not experienced before when working in 3000-4000m depths," it said.
The news item in today's Dominion Post has more on the sinking of the ship. Of the 311 souls who escaped, 104 died, all but six of them after reaching the overcrowded lifeboats.
The main body of the lifeboat fleet made St Helena, but three were lost. Of those, one reached South America, with just two people alive, an officer and a female passenger. As John Kingsford said, "I don't think people really understand what they [the merchant seamen] did and the losses there were in order to keep our country alive."
Kingsford's company keeps an unspecified proportion of the retrieved treasure. He now has his eye on other wrecks -- also unspecified.