Transcript for The Long and Complicated Task of Finding Flight 370
And now, we move to the Indian ocean and the new energy in the search for the black boxes and the missing passenger plan. ABC's Clayton sendell shows us the perils three miles down at the bottom of the ocean. Reporter: Two dozen ships and planes today, searching the Indian ocean from above. Amid growing confidence about what lies below. We have very much narrowed down the search area and we are very confident that the signals that we are detecting are from the black box on mh370. Reporter: But those signals haven't been heard since Tuesday and without them, no way to home in. So teams will soon turn to this sonar scanner to begin looking for wreckage. It's slow going. How long would it take? It's probably a month and a half to two months of effort. Reporter: It takes that long? Yes, it does. Reporter: The sea floor here rests under 15,000 feet of water, a remote, pitch black alien landscape of plains and mountains 12,000 feet high. When or if Malaysian airline 370's boxes are found, the machine like this will bring them up. It is a mystery of clues hidden at the bottom of a vast ocean, that may take years to solve. Clayton Sandell, ABC news, Perth, Australia.
This transcript has been automatically generated and may not be 100% accurate.