the ocean? >> it's much more difficult. we're now at day 20 of the problem. >> reporter: the possible good news comes in what the black line represents in realtime. >> operating near the area of wear our imagery says it is located. >> van gurley's company has similar models that actually help the coast guard find people who are lost at sea. they take a report of where someone has been lost and project currents and drift ahead to where people may be drifting in the water and where the coast guard can start a search. wolf? >> brian todd, as usual, thank you. joining us now, the oceanographer from the research center at new south wales and also joining us is colleen keller from metron which helped search for air france flight 447.