deep for bluefin-21 to scan for wreckage. >> the areas north of that ping were too deep for the bluefin. sure. could it be north? absolutely. it could be north. >> reporter: what's next? reviewing all existing data including inmarsat and satellite data. from there, defining a search area that could be 23,000 square miles along the arc in the south indian ocean. a ship will map the ocean floor in that area preparing for the day private companies are hired to continue the underwater search. so for some perspective, bluefin searched some 230 square smiles. it's going to take about three months for the mapping of the ocean floor in that area and we know that the next phase of searching, when it begins, it will be a long haul. they are estimated it could take