IN THE INDIAN OCEAN They have searched for Flight MH370 with satellites from space, with planes from the air and with ships on the sea. On land, they've scoured radar data, working day and night. What they haven't done, until now, is to look underwater.
As I write, I'm watching the first ship leave port to do just that; a ship that will provide the world with the first eyes and ears under the waters where the plane is thought to have gone down.
The Australian naval vessel Ocean Shield is leaving Fremantle on Monday with investigators and sophisticated technology on board.
It is carrying an underwater drone - a small, unmanned submarine fitted with cameras that can see objects deep down in the ocean.
It is also carrying a black box locator that will be towed behind the ship to detect the pings sent out by the cockpit voice recorder and flight data recorder on the missing Boeing 777.
Soon, the world will have eyes and ears underwater to hunt for the doomed plane.
But the mission has serious handicaps: the ship is leaving port late, and without any clear idea of the best place to go.
So far, not a single piece of debris has been found that would give the ship s crew target to aim for. It will sail 1,150 miles from the Australian coast to the new search zone, lower the locator into the water and hope.
The locator device can hear sounds for miles around, but the search area is the size of New Mexico.
U.S. Navy Captain Mark Matthews, who is in charge of the equipment, has warned that it could take years to find the Boeing 777 because of the lack of positive information about where to go. The vast ocean could take an untenable amount of time to search, he said.
Debris from Air France Flight 447, which crashed into the Atlantic Ocean in 2009, was found within days and yet it took two years to find the wreckage, and its black box, on the sea bed.
The other problem for this ship is that it's in a race against time. The transponder on the black box is powered by batteries that will begin to fade and die after 30 days. That's next Monday. So the ship has exactly a week to sail more than 1,000 miles and begin combing the ocean before the pinger locator starts to lose any chance of hearing signals.
Every nation and every one of the 1,000-plus air and sea crew members searching for the plane is doing their best. But neither the most sophisticated technology available, nor the human eye, has detected anything positively linked to MH370.
It is clear that Ocean Shield is sailing more in hope than in expectation as it tries to solve what Australia's prime minister called this extraordinary mystery.