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Chinese sailor Guo Chuan went missing after being thrown into the water by high winds or a rocking boat during his trans-Pacific sailing, Guo's support team said on Thursday.
The team said he was suspected to have fallen in the water between 15:15 and 15:30 Tuesday Beijing time.
The 51-year-old Chinese sailor was attempting to sail from San Fransico to Shanghai in 20 days or less for a new solo trans-Pacific world record.
The U.S. Coast Guard have suspended the active search for the missing mariner, who lost contact while sailing his 97-foot super trimaran 500 nautical miles off the west of Hawaii.
According to the U.S. Coast Guard, an HC-130 Hercules airplane crew, sent from Coast Guard Air Station Barbers Point, conducted six search patterns in the vicinity of the trimaran. The USS Makin Island deployed a Navy MH-60 Seahawk helicopter once they were in range to attempt contact with Guo. Their hails over the radio went unanswered and weather conditions prevented safe deployment of a rescue swimmer to the vessel.
They followed up by deploying a rigid-hulled inflatable boat and crew to conduct a boarding of the trimaran. The boatcrew confirmed Guo was not on the vessel although his life jacket remains aboard.
Marine and navigation experts on Guo's team blamed Guo's disappearance on the jib, a triangular staysail that sets ahead of the foremast of a sailing vessel, which was seen broken from the ship and floating on the water.
Following a research of videos, photos and phone transcripts from rescuers, the experts agreed on two scenarios that led to Guo's disappearance.
When Guo tried to lower the jib against high winds, a difficult task for a solo sailor, the jib suddenly fell. Guo tried to prevent the sail from dropping into the water while standing at the narrow head of the ship. The ship rocked and Guo fell.
The second scenario could happen when Guo dealt with an accidental fall of the jib. Guo unknotted the harness for wider movement on the ship to drag the jib onboard, which got heavier after getting wet. A heavy wave could have thrown the sailor off board.
An expert on Guo's team said it was difficult for a solo trimaran sailor to lower a jib or drag a soaked sail from the water.
In any of two cases, the sailor has to untie his harness to complete the job, he said.
Guo's team said the sailor had been in a normal mental and physical condition before the accident happened.
Guo set sail on his trimaran near San Francisco, embarking on a solo voyage to Shanghai. He was last heard just after 15:00 Tuesday Beijing time when his trimaran sailed 500 nautical miles off the west of Hawaii, his support team said.
The Chinese sailor aiming to set a new solo non-stop trans-Pacific world record, piloted the 'Qingdao China' west across the starting line under the iconic Golden Gate Bridge.
Guo, who had a world record to his name for a 138-day solo non-stop circumnavigation, told a Xinhua reporter in an earlier interview that the greatest fear for a sailor was to fall in the water.
The current trans-Pacific speed record is 21 days, set by crews on board the Italian Maserati.
