The search for the missing Malaysia Airlines Flight 370 will go underwater starting today.

The black box of the missing jet has been the primary part of the search that people have been focusing on.

TIME reports that investigators stopped the use of towed pinger locators to find the missing jet black box, and instead has turned to an unmanned submarine in order to find wreckage on the ocean floor off Australia's west coast.

Angus Houston, who is in charge of the search for Flight 370 has stated, "We haven't had a single detection in six days so I guess it's time to go underwater. I emphasize this will be a slow and painstaking process."

Although four pings have been heard from the Malaysia Airlines jet's flight recorders, the devices' batteries only last 30 days.

Today marks day 38 since the plane, which had 239 passengers and crew members, disappeared mysteriously.

From Monday evening, a Bluefin-21 unmanned underwater vehicle will investigate the ocean floor using side-scan sonar to search for wreckage.

The submarine will reportedly operate on a 24-hour-continous cycle. It will take two hours to reach the ocean floor, 16 hours to search 40 sq km, two hours to return to the surface and then four hours to download and analyze collected data.

The fact that the search has gone underwater has made some lose hope for the search for Malaysia Airlines Flight 370.

It had been continuously emphasized that the black box of the missing jet was the core part of the search.

When Ocean Shield picked up the pings last week, Australian Prime Minister Tony Abbott made sure to explain to the public that the search would be an ongoing, long process, reports Fox News.

Abbott stated, "There's still a lot more work to be done and I don't want anyone to think that we are certain of success, or that success, should it come, is going to happen in the next week or even month. There's a lot of difficulty and a lot of uncertainty left in this."