IN JUST a few weeks, the southern Indian Ocean will be transformed into a terrifying cauldron of giant crashing waves and freezing winds as winter sets in, placing the lives of those hunting for MH370 at even greater risk.

Texas-based exploration company Ocean Infinity is set to receive up to $90 million if its state-of-the-art search vessel Seabed Constructor finds the lost Malaysian Airlines Boeing 777 within 90 days.

Horrifying photographs of waves crashing across the Fugro Discovery, one of three search vessels deployed in the previous Australian-led search for the plane, during the winter months illustrated just how perilous that mission was.

And conditions will be no less treacherous for Seabed Constructor and its support vessel MV Maersk Mariner when the eight-month-long winter brings brutal swells and screaming winds to the area.

Aviation consultant and journalist Geoffrey Thomas once described the southern Indian Ocean in winter as “the worst place in the world” and predicted that even if the wreckage was found, any recovery mission could take months or even years.

With the fourth anniversary of the plane’s disappearance just days away and more than 8000sq km of the new search area already scoured with no result, the pressure on Ocean Infinity is building by the hour.

If it does find the wreckage within the three-month time limit, the search area will be in the full throes of winter fury and recovery may not even be possible.

Such an expedition would require cutting-edge technology, would likely last months and potentially cost more than the maximum $90 million reward Malaysia is offering Ocean Infinity, according to deep-ocean salvagers.

“They (searchers) are working at the extreme edge of what’s capable,” South African salvage master Nick Sloane, who led the operation to recover the stricken Italian cruise ship Costa Concordia, told AFP.

“(But) the benefits to the manufacturers of the aeroplane, operators and the families are that if you actually locate the wreckage, it’s worthwhile to go ahead and take the next step and recover it.”

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To aid the previous search, which was the largest in aviation history — the ocean floor was mapped in detail for the first time, revealing the varied underwater terrain.

It showed seafloors more than 4700m deep, vast mountains 1500m high and kilometres wide, deep canyons and massive underwater landslides of sediment, according to Geoscience Australia.

#MH370 7 Day Surface Wind forecast for the Indian Ocean from Passage Weather. Watch the last few frames of this and you will see why I am becoming concerned about the weather for the middle to end of next week. (the system coming off Madagascar) I will be watching this closely pic.twitter.com/tnt2b459Pn — Kevin Rupp (@LabratSR) February 27, 2018

If debris is found between 2000m and 6000m — a depth known as the abyssal zone — salvagers would work in a perpetually dark and near-freezing region where the pressure can reach up to 9000 pounds per square inch (psi).

Wreckage has been recovered from such depths previously: Air France 447 at nearly 4000m in the Atlantic, the cargo ship El Faro (4500m) off the coast of The Bahamas, and South African Airways 295 (4900m) off Mauritius — far deeper than where oil and gas companies operate.

Machines that can operate at such extremes include deep-ocean operator Odyssey Marine Exploration’s remotely-operated vehicles, which have frames constructed out of high-strength aluminium. A handful of other companies have similar technology.

The ROV, tethered to the mother ship, is fitted with LED lights that illuminate the dark environment and can record high-definition footage, Odyssey Marine’s chief operating officer John Longley told AFP.

The submersible — remotely driven by pilots on a surface ship — has two manipulator arms that function like “human hands” and can retrieve smaller objects.

Deep-sea shipwreck hunter David Mearns said larger parts such as the jet’s wings can be brought to the surface using baskets or slings.

He said such underwater journeys could take several hours with the overall mission possibly lasting up to half a year.

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“But once you get into a position on the seabed, it’s remarkable the dexterity of these ROVs (remotely operated vehicles) in terms of what they can do,” Mr Mearns told AFP.

On the surface, the ROV pilots would be supported by a vast array of hardware — including support vessels — as well as crew that could number more than 100, senior salvage master Wytse Huismans of high-profile global operator SMIT Salvage told AFP.

The team would also have to grapple with rough seas — which could make its vessels inoperable during the height of winter in a few months’ time — and the remoteness of the area, which is several sailing days from Australia’s Fremantle port.

But not all parts of the wreckage have to be recovered to determine what may have happened, the experts said, stressing that the black boxes could still hold key clues to the plane’s disappearance.

Other parts of the wreckage may be hauled to the surface if needed to help unravel the mystery.

Mr Mearns said the debris is likely scattered within a 1.5km field.

“So even if it’s in a challenging environment in terms of the terrain, they will have the capability to handle it, to recover it,” he said.

— With AFP