Underwater search for Emiliano Sala's plane begins
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The planned search area, which is based on the plane's last radar contact, is approximately 24 nautical miles north of Guernsey.
An underwater seabed search for the missing plane that was carrying football player Emiliano Sala and pilot David Ibbotson began on February 3.
Cardiff City's new signing Sala and the aircraft's pilot, David Ibbotson, have been missing since their plane disappeared over the Channel last week.
Britain's Air Accidents Investigation Branch (AAIB) said its Geo Ocean III vessel arrived on Sunday morning to the search area.
Together with a privately-funded vessel, it is conducting sonar surveys off Guernsey.
The planned search area, which is based on the plane's last radar contact, is approximately 24 nautical miles north of Guernsey.
The 28-year-old Argentina-born forward had been en route from Nantes in western France with pilot Ibbotson to make his debut for Welsh team Cardiff City when the plane disappeared over the English Channel on January 21.
AAIB said it was informed on Monday (January 28) that part of a seat cushion had been found on a beach near Surtainville on the Cotentin Peninsula in northern France. A second cushion was found in the same area later that day.
Rescuers scoured about 1,700 square miles (4,400 square km) after the single-engined Piper Malibu plane went missing but had failed to find a trace of the aircraft until Monday.
The plane had been cruising at 5,000 feet (1,525 m) when the pilot requested to descend to a lower altitude on passing Guernsey. It then lost radar contact at 2,300 feet (700 m).