Search and rescue authorities are travelling by boat to the site in the Marshall Islands where an empty and submerged boat was spotted by a U.S. Navy C-130 aircraft yesterday.
Authorities say they are yet to officially confirm whether the air sighting off the coast of Arno Atoll yesterday is the missing boat of four passengers travelling to Majuro.
The Deputy Chief Secretary, Joelik Tibon, says relatives continue to hold out hope all the missing passengers survived.
"We cannot stop hoping, especially the relatives, because people have been lost before, a lot longer and they survived. The thing is that we are still hopeful."
Joelik Tibon is asking the public to report any signs of boat debris to authorities as the search continues for the passengers, including one American.