Missing Malaysian Plane #MH370 Latest: search goes under water

The hunt for Malaysia Airlines Flight 370 took on increasing urgency Friday as searchers began scouring the ocean floor and the batteries powering its locator pinger approached the end of their expected lifetimes.

If they die, so too could investigators' best hope of determining what caused the jetliner to vanish last month from radar screens.

Fourteen aircraft and 11 ships were involved in Friday's activities, reported the Australian agency coordinating the search efforts.

The Australian Maritime Safety Authority has determined a search area of about 84,000 square miles (217,000 square kilometers), 1,000 miles (1,700 kilometers) northwest of Perth.

Weather in the area was good, with visibility greater than six miles (10 kilometers).

But searchers were fighting steep odds.

"Really the best we can do right now is put these assets in the best location -- the best guess we have -- and kind of let them go," U.S. Navy Cmdr. William Marks told CNN. "Until we get conclusive evidence of debris, it is just a guess."

Bill Schofield, an Australian scientist who worked on developing flight data recorders, said, "If they do find it, I think it'll be remarkable."

The decision about where in the southern Indian Ocean to focus British and Australian naval ships equipped with sophisticated listening technology was nothing more than an educated guess of where the plane may have hit the water.

On Friday, ships did report sightings of objects, but none were linked to plane debris.