The GO Phoenix, a Malaysian government contracted ship, is the first of the three vessels that arrived in the search zone and the fleet will spend around a year to hunt for the wreckage of MH370 in an area of about 60,000 sq km, Xinhua reported.
One of the largest international aviation searches in history was underway after MH370 disappeared with 239 people on board during its journey from Kuala Lumpur to Beijing.
However, the multinational search team had to stop the hunt after nearly two months of fruitless work and the related countries began to map the sea floor which was crucial to continue the underwater mission.
According to the plan, GO Phoenix will use an underwater sonar device called towfish to operate over the seabed.
When the device detects any suspicious wreckage, the ship would put down highly sensitive camera equipment to film it and decide whether it belongs to the MH370.
GO Phoenix would stay in the mission area for 12 days before heading to the Australian coast for refuelling and supply.
Two other ships provided by Dutch contractor Fugro would join the GO Phoenix later this month.
ATSB Chief Commissioner Martin Dolan said: “All we want to indicate to everyone is that we’re cautiously optimistic… We’ll locate the missing aircraft.”