The operation was carried out by Deep Ocean Search (DOS) under a contract with the Ministry of Transport, London.
In August, 1942, a group of four German U-boats, including the U-68, left Lorient for operations off Cape Town as the Eisbar group. This was the U-68’s fifth war patrol during which she sank eight ships and then left the Cape Town area for home on Oct 29.
In October, the passenger-cargo liner City of Cairo, 8,034grt, under the command of Captain William Rogerson, sailed from Bombay for Britain, via Table Bay with 100 passengers, 186 crew and 10 gunners and was carrying a general cargo, including the silver rupee coins.
At about 2030, on Nov 6, 1942, five days after leaving Cape Town, the City of Cairo was about 500 miles south of the island of St Helena when she was hit by two torpedoes from the German submarine U-68. The ship had to be abandoned but several of the lifeboats had been seriously damaged in the torpedo explosions.
Twenty-two passengers, 79 crew and three gunners died. The survivors were in the lifeboats when the U-boat approached to question Capt Rogerson. The U-boat captain, Karl-Freidrich Merten, told him how far he was from Brazil and left saying, “Goodnight, sorry for sinking you.” Capt Rogerson took command of one lifeboat and decided that his boat would set out and try to find help for the survivors. They were picked up by the cargo liner Clan Alpine, 5,442grt, of Clan Line, and were landed on St Helena. Other survivors were rescued by the cargo liner Bendoran, 5,567grt, of the Ben Line, Leith, and were landed at Cape Town. One lifeboat was found by a Brazilian minelayer on Dec 27 with just the Third Officer and a woman passenger onboard, all the others having died.
The other lifeboat carried 54 survivors, 23 Europeans including two women and a 12-year-old girl, and 31 Lascars. After five weeks, only three survivors, two Europeans crew members and the young girl, were on board when the lifeboat was found by the German blockade runner Rhakotis, of Hamburg America Line, Hamburg, bound from Japan to Germany.
DOS began the operation to locate the wreck in November, 2011. The positions given by the U-boat and that from the ships officers were different so a large box search was carried out. The seafloor was difficult with ridges and canyons throughout the area and the water depth varied between 5,100m and 5,500m.
“A small target with little height and reflectivity was seen in amongst a hillside and was subsequently dived upon. It turned out that it was a wreck and the identity was finally confirmed to be that of the City of Cairo,“ said DOS. “The ship was broken in two and buried deep in the seafloor silt. Parts of the ship had meters of mud heaped upon it.
Using a remote recovery system, DOS set a world depth record for the recovery of the coins and the team left a plaque commemorating its finding and visiting the ship before it left the site finally on Sept 25, 2013.