With the clock ticking on the battery life of missing Flight MH370's black box, the international search group has shifted its focus from the surface of the southern Indian Ocean to the sea floor.

The battery life of the Boeing 777's flight data recorder, commonly known as the black box, on board the Boeing 777-200ER estimated to expire on Monday, so search teams began employing the use of underwater tools on Friday in an effort to locate the black box of the Malaysia Airlines plane, which is believed to have gone down somewhere in the southern Indian Ocean. Among the tools being employed by the search teams is the Bluefin Robotics autonomous underwater vehicle (AUV), named Bluefin-21, which is capable of searching and mapping the sea floor at a depth of 4500 meters, approximately 2.8 miles below sea level.

While the Bluefin-21 AUV is responsible for mapping the ocean floor through the use of sonar, the U.S. Navy has deployed a towed pinger locator devic that is capable of detecting and locating emergency pings from aircraft black boxes, such as the one on board Flight MH370. In addition to the U.S. Navy’s towed pinger locator, the Royal Navy has employed a similar device from onboard the HMS Echo.

Search efforts on Friday resulted in the discovery of several pieces of debris, none of which were associated with Flight MH370, according to the Australian Join Agency Coordination Center.

However, the international search group continues to scour the waters below for any sign of the missing plane, which had 227 passengers and 12 crew members on board.

Should the battery of Flight MH370’s black box die before it is located, it is possible that it may not be found for years, as in the case of Air France Flight 447, which crashed into the Atlantic Ocean in 2009.

Take a look at the current search efforts for Malaysia Airlines Flight MH370 in the photos below.