Potential leads on the missing Malaysian Airline Flight 370 keep coming. So do the setbacks and frustrations.
Monday's search ended without finding anything significant, Australian officials said. Four orange objects spotted by search aircraft and earlier described as promising turned out be nothing more than old fishing gear, they said.
Underscoring the difficulty of the search, U.S. Navy officials loaded underwater locating gear aboard an Australian naval support vessel and set out to sea Monday evening, but won't be able to make use of the equipment until searchers narrow the search zone.
U.S. Navy Cmdr. William Marks told CNN's "State of the Union" that his team needs a conclusive piece of debris to narrow down the search area before deploying the equipment.
"We have to be careful not to send it in the wrong place," he said. "But we also wanted to get it out there as close as we can to what we believe is the right place."
The gear includes a pinger locator that's towed behind a ship and scans for the sound of the locator beacon attached to the plane's flight data recorder. Also on board is a remotely operated submersible that can look for wreckage on the ocean floor.
It will take the ship, the Ocean Shield, three days just to get to the search zone, leaving precious little time to locate the plane's flight data recorders before the batteries on its locator beacon run out. The batteries are designed to last 30 days; the plane has been missing 23 days.
Under favorable sea conditions, the pingers can be heard 2 nautical miles away. But high seas, background noise, wreckage or silt can all make pingers harder to detect.
In this case, searchers barely know where to look at all.
"We are searching a vast area of ocean, and we are working on quite limited information," Australian Prime Minister Tony Abbott told reporters Monday. "Nevertheless, the best brains in the world are applying themselves to this task. ... If this mystery is solvable, we will solve it."
And he vowed to keep looking.
"The intensity of our search and the magnitude of our operations is increasing, not decreasing," he said.
Ten aircraft and 11 ships scouted more than 98,000 square miles (254,000 square kilometers) of Indian Ocean on Monday looking for the missing plane, Malaysia's acting Transportation Minister Hishammuddin Hussein said Monday.
Flight 370 vanished March 8 while flying from Kuala Lumpur to Beijing.
A new Australian Joint Agency Coordination Center is being formed to synchronize search efforts among Australian agencies and other countries taking part in the search, Hishammuddin said.
And Malaysia will ask the United States about the possibility of deploying more military assets, he said.