"Unknown Magnetic Phenomenon" and a maritime mystery: What has been causing ships to sail in circles?
From a spacecraft forum:
http://www.satobs.org/seesat/Jun-2020/0051.html
Interesting Notice to Mariners..I assume the date was June 2nd.
This is within the SAAZ but I didn't think it affected surface vessels.
I wonder if this confirms the changes recently found by ESA's SWARM satellites ?
NL BURUM LES 4-JUN-2020 09:51:23 635672
SECURITE
031021 UTC JUN
NAVII/132 OF 2020
-
SOUTH ATLANTIC OCEAN - NE SECTOR
-
CHARTS SAN 1, 2, 5, 27(INT 204)
-
M/V WILLOY EXPERIENCED UNKNOWN MAGNETIC
PHENOMENON AFFECTING ONBOARD ELECTRONIC AND
NAVIGATION EQUIPMENT ON 25 JUN 20 IN FOLLOWING
POSITION
-
32 - 26.0S 011 - 55.0E
-
POSSIBLE DANGER TO NAVIGATION WITHIN 100 NM RADIUS FROM THIS
POSITION.VESSELS TO NAVIGATE WITH EXTREME
CAUTION AND REQUESTED TO REPORT ANY UNUSUAL
MAGNETIC PHENOMENON TO CAPE TOWN RADIO OR
MRCC CAPE TOWN
-
CANCEL THIS MESSAGE 170800 UTC JUN 20
Related news article (also touching on maritime navigation issues near China, which may or may not be related, but either way is interesting in its own right)
https://www.fixradio.co.uk/news/weird-stories/a-maritime-mystery-what-has-been-causing-ships-to-sail-in-circles/
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.
… Modern ships like the Willowy use something called a gyrocompass instead, which finds true north as determined by gravity and the axis of the Earth's rotation rather than magnetic north.
The gyrocompass is used alongside the ship's other systems to detect true north, identify the vessel's course, and steer it. If it was to fail it could cause exactly the issues which the Willowy was experiencing.