
Something bizarre happened to an oil tanker sailing near Cape Town on Sunday - ships were sailing in circles, unable to steer.
In the early hours of Sunday 31 May, senior officers aboard the oil tanker Willowy were called to the bridge to be told that their ship and four others in its vicinity were mysteriously sailing in circles, unable to steer, and on course to converge.
It must be easy to panic at sea. The immediate presumption was that strong currents were pushing the vessels around, but there were
no such currents where the ships were sailing in the south Atlantic Ocean, west of the South African city of Cape Town.
Ships appearing to sail in circles have become an increasingly common and mysterious phenomenon near a number of ports on the coast of China, especially near oil terminals and government facilities - but
nothing had been seen where the Willowy was.Researchers monitoring these bizarre circles near the Chinese coast believe they are probably the result of systematic GPS manipulation designed to undermine a tracking system which all commercial ships are required to use under international law.
Known as AIS (automated identification system), the technology broadcasts unique identifiers from each vessel - along with the vessel's GPS location, course and speed - to other ships nearby.
These signals are even collected by satellites and used to monitor suspicious behaviour, including smuggling, illegal fishing, and - most relevantly - trade in sanctioned oil.
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