The United States Coastguard has begun a fourth day of searching for a missing Palau plane and its three passengers.
The Cessna aircraft was on its way to take footage of a Palauan boat's pursuit of an illegal fishing vessel when it disappeared on Sunday.
It was carrying two Palau police officers, Earl Decherong and Willy Mays Towai, and was piloted by an American, Frank Ohlinger.
A Coastguard spokesperson, Lieutenant Richard Russell, says the men could still be alive.
"In this area of the world we've had some incredible search and rescue cases where we've actually met with individuals who have survived at sea for months, clinging onto whatever they could, whether it was what's left of their vessel, debris - so certainly at this point anything could happen."
Lieutenant Richard Russell says the search has covered more than 21,000 square kilometres of ocean.