Sub Being Deployed in Flight 370 Search

Search crews have stopped seeking pinger signals in the search for missing Malaysia Airlines Flight 370, and an underwater vessel will now be deployed in the southern Indian Ocean, a process that officials are describing as painstaking and slow.

Angus Houston, retired Australian Air Chief Marshal, who is head of the joint agency coordinating the search for the missing jetliner, discussed the updates at a Monday press conference. Houston said the Bluefin-21 will be deployed, creating a sonar map of the area to chart any debris on the sea floor.

Read more: Malaysia Airlines Flight 370: What Happens Now?

Crews had picked up a series of underwater sounds over the past two weeks that were consistent with an aircrafts black boxes. But the black box pingers only have battery life for about a month and given the planes March 8 disappearance, officials believe too much time has passed for any new signals.

"We haven't had a single detection in six days, and I guess it's time to go under water," Houston said.

Officials are hoping to find the black boxes in order to understand what happened to the jetliner, which disappeared with 239 people on board.

Houston warned that the switch to the submarine remains a slow process. The Bluefin-21 will take 24 hours to do each mission, including two hours to dive, 16 hours to search the bottom, then two more hours back up and four hours to download data.

Additionally, the sub will need up to two months to canvass the current underwater zone. The deepest the sub can dive is 15,000 feet the depth that the signals were coming from.

Search crews will continue scouring the area for visual debris, with 12 planes and 15 ships involved in todays efforts.

The Associated Press contributed to this report.