About 200,000 square kilometres of the search area has been surveyed so far.
Fugro Discovery arrived back in the search area on December 4, while GO Phoenix returned last Tuesday, and both have recommenced underwater search operations.
Danica Weeks, whose Kiwi husband Paul was on the missing flight, wrote an article for the Sunday Times.
She said when she and her two young children said goodbye to him they never thought it would be for the last time.
"But now, March 7 is permanently engraved in my mind and often on rewind," she wrote.
"Not only as the day we kissed Paul goodbye at Perth Airport, but because mentally, for me, it is still March 7."
Ms Weeks said not knowing what really happened to her husband continued to haunt her.
"Every waking minute, your mind runs scenarios of what might have happened," she said.
"You are searching the news constantly for any small piece of information that may give you a clue to their whereabouts, and your heart pounds every time the phone rings. Is this it? Have they found something?"
- AAP