Workers on the ship Ocean Shield stand alongside the U.S. Navy's Bluefin-21 autonomous underwater vehicle at Her Majesty's Australian Ship (HMAS) Base Stirling, south of Perth, May 10, 2014. The ... more 
Workers on the ship Ocean Shield stand alongside the U.S. Navy's Bluefin-21 autonomous underwater vehicle at Her Majesty's Australian Ship (HMAS) Base Stirling, south of Perth, May 10, 2014. The Australian naval vessel carrying the underwater drone involved in the search for missing Malaysia Airlines Flight MH370 left port on Saturday on its second mission to scan part of the Indian Ocean sea floor off Western Australia where the longest sonar "ping" was heard over a month ago. REUTERS/Morag MacKinnon (AUSTRALIA - Tags: MILITARY DISASTER MARITIME TRANSPORT) less 
1 / 28
Reuters | Photo By STRINGER / REUTERS
Sat, May 10, 2014 8:47 AM EDT