ATSB announced in April that that search area had been doubled in size, even though the first priority area has still not been completely searched.
If Fugro ends up empty-handed, it will most likely be because the plane didn't crash where officials thought, said Geoff Dell, a former Australian Airlines air safety investigator and current head of accident investigation at Central Queensland University.
But it's still possible, he said, that searchers "may have driven over the top of it and didn't see it."
Danica Weeks, a New Zealander whose husband Paul was aboard Flight 370, has been aboard a Fugro search ship and trusts that the company knows what it is doing. But she also wants the data reviewed in case a crucial clue was missed.
She added: "I'm losing faith. I think any human being in this situation would."