Now towed pinger locators will be used to search the southern Indian Ocean for missing Malaysia Airlines flight MH370, Australian officials say.
Two ships with pinger locator capabilities will search a 240km track under water in the hopes of recovering the plane's black box, BBC reports.
More than 14 planes and nine ships will also search for the plane on Friday.
The Malaysia Airlines plane disappeared on 8 March en route from Kuala Lumpur to Beijing. It was carrying 239 people.
It is believed to have crashed in the southern Indian Ocean, although no confirmed debris has been found from the plane. The search is being coordinated from Australia.
Angus Houston, head of the Joint Agencies Coordination Centre (JACC) leading the search, said that two ships had “commenced the sub-surface search for emissions from the black box pinger.”
"The two ships will search a single 240km track converging on each other," Houston said.