"A search aircraft, sent from Honolulu, found the main sail in water, broken off the vessel, but didn't see Guo on the deck. All attempts to contact the sailor have failed."
The U.S. Navy had sent two ships to the site of Guo's vessel, his team added.
Guo, who set sail from San Francisco on Oct. 19, was aiming to complete his journey to Shanghai in 18 days. Italian Giovanni Soldini owns the speed record after completing the voyage in 21 days in 2015.
Guo already has two records to his name, having set the pace to beat in the 40-ft solo nonstop circumnavigation in 2013 and the Arctic Ocean Northeast Passage non-stop mark in 2015.
"We have been working hard for the past two weeks to refit the boat and finally today I am going to set sail," Guo said prior to setting sail from San Francisco.
"I am very confident to go now. See you in Shanghai within 20 days."
(Reporting by Shravanth Vijayakumar in Bengaluru)
