Tony Romeo is on a mission to find the wreck of trailblazing aviator Amelie Earhart's plane in the middle of the Pacific Ocean.

Last year the deep-sea explorer spent millions of dollars on a search after sonar images showed a plane-shaped object in the murky depths — but it turned out to be just a pile of rocks.

Speaking exclusively with the Daily Mail, Romeo said his method remains sound, that he knows roughly where Earhart's plane went down, and that though it will be a long slog he is sure the hard grind will pay off… eventually.

His mission underscores the allure of the famed pilot, whose disappearance on a round-the-world flight attempt in 1937 was followed by decades of conjecture about her fate and costly expeditions to remote islands to find her plane.

'Amelia wants to come home, she wants to be found,' says the CEO of South Carolina-based Deep Sea Vision.

'I don't think she wants to stay at the bottom of the ocean for the rest of eternity, and we are 100 percent committed to finding her, finding her airplane.'

The 44-year-old focuses on the waters around Howland Island — the refueling stop where Earhart was headed before she disappeared in 1937.

He's not alone.

Deep sea explorer Tony Romeo, left, pictured with Corey Friend, says he aims to return to Howland Island to recover the wreck of Amelia Earhart's plane

American trailblazer Amelia Earhart poses atop her Lockheed Vega Monoplane in about 1932

David Jourdan, the president of Maine-based Nauticus, and Bob Ballard, who located the Titanic in 1985, have plumbed the same depths for Earhart's Lockheed Electra. 

Likewise, they have yet to get a hit.

Earhart and her navigator, Fred Noonan, disappeared in the Pacific on July 2, 1937, en route from Papua New Guinea to Howland Island.

Her bid to become the first female pilot to circumnavigate the globe ran into strong headwinds, and she radioed that she was running low on fuel.

The US Navy scoured the area for 16 days but found no trace of her twin-tailed monoplane.

The loss of an aviation pioneer who had inspired women to chase their dreams sent shockwaves around the world.

The longstanding official theory is that the plane ran out of gas, crashed and sank into deep waters off Howland Island.

But the absence of a wreckage spawned a slew of alternate explanations about the tousled-haired heroine's fate.

Theories have veered into the absurd, including abduction by aliens, or Earhart living out her days in New Jersey under an alias.

Some speculate Earhart and Noonan crash-landed on Mili Atoll, 800 miles northwest of Howland, and were taken prisoner by the Japanese and transported to Saipan, where they died in captivity.

Renting a vessel in the mid-Pacific costs $30,000 a day, and it's 10 days' sailing to reach the target zone 

Romeo uses a Hugin 6000 underwater drone to scour the sea bed around Howland Island

Earhart was on one of the final legs of her round-the-world flight in 1937 when she disappeared 

Others say Earhart's route put her on course for Nikumaroro Island, 400 miles to the southeast. 

A team from Oregon will head there in November to probe a plane-shaped metallic object that's sitting in sludge in a lagoon.

Past expeditions to Nikumaroro have uncovered bones, a campfire, clothing, and navigational gear, that may suggest Earhart ended her days there.

Romeo says many have been drawn by the Earhart puzzle into draining their bank accounts.

'It's the biggest, longest, unsolved mystery out there,' he says.

In all the various searches across the Pacific, no one has found a verified plane part or bone fragment.

Romeo says armchair detectives have spent too long dreaming up alternatives to the mainstream crashed-and-sank theory.

The Electra won't be found by analyzing Earhart's last-known coordinates, wind speeds and the complexities of navigating across the international date line, he says.

'Nobody's going to solve this riddle using a math equation,' says the pilot and former US air force intelligence officer.

Earhart (born 1897) standing in front of the Lockheed Electra in which she disappeared in 1937

Last year Deep Sea Vision released sonar images they believed might be the remains of Earhart's plane but it turned out to be a pile of rocks

Earhart's plane vanished on July 2, 1937. In the last in-flight radio message, Earhart said: 'We are on the line 157 337 …. We are running on line north and south.' These numbers refer to compass headings – 157° and 337° – and describe a line that passes through the intended destination, Howland Island

Deep Sea Vision and other teams have tried to pinpoint the crash location by scanning the ocean floor.

Romeo used a Hugin 6000 drone to scour thousands of square miles of sea bed around Howland Island.

The 24-foot underwater device focusses on the areas to the north and south of the island along Earhart's course.

A scan early last year showed what appeared to be the outline of the iconic plane on the seafloor — but a return mission in November revealed that it was just a pile of rocks.

Romeo plans to go back within two years to scan another 1,500 square miles of sea bed.

The challenges are daunting, he adds.

The underwater terrain, with its ravines, is 18,000 feet deep in places and tough to chart.

The mystery of Amealia Earhart's disappearance still captures the imaginations of millions

Researchers will in November investigate a mystery object on Nikumaroro that they believe is Earhart's lost Electra

Marine explorer David Jourdan says all the signs point to the Electra being in the waters around Howland Island

Many areas require multiple scans and the drone's batteries have to be recharged regularly.

Ships cost $30,000 a day to rent and it is 10 days' sailing to the nearest major port, he adds.

Still, at depths of the ocean, the cold water and calm currents may well have preserved the Electra these past nine decades, experts say.

Jourdan, another mapper of Howland's waters, says it's like 'searching for a contact lens on a football field in the dark using a penlight for illumination.'

'It can be done, but it takes careful, methodical work,' he adds.

His team has scanned 3,600 square nautical miles using sonar on previous missions and plans a 'new expedition' in the future.

He estimates that an area of 6,000 square nautical miles needs to be covered in all — that's about the size of New Jersey.

Like Romeo, he says the crashed-and-sank theory is far more likely than Nikumaroro or the other explanations.

'Our work over the years has convinced us that Amelia and Fred were close to Howland Island a short while before they ran out of fuel,' Jourdan told Daily Mail.

The mystery of Earhart's disappearance still captures the imaginations of millions around the world.

A one-woman show about the 'pioneer in aviation' it touring the northeast; an airport terminal bearing Earhart's name will open in Indiana in August.

Finding the plane is a 'work of passion,' says Romeo.

'Wreck hunting is not the kind of business you're going to get rich out of,' he says.

'I want to see this plane sitting in a museum so I can go visit with my children some day and tell them we made a run at it.'

WHAT ARE THE THEORIES ON AMELIA EARHART'S FINAL DAYS?

Theory One: Amelia Earhart and Fred Noonan crash into the Pacific a few miles short of their intended destination due to visibility and gas problems and die instantly.

Earhart in 1928

Theory Two: Earhart and Noonan crash land on the island of Nikumaroro, where they later die and are eaten by coconut crabs, which hunt for food at night and grow up to three-feet long. The name comes from the crabs' ability to open the hardened shells of coconuts.

Theory Three: Earhart and Noonan veer drastically off course and crash land near the Mili Atoll in the Marshall Islands. They are rescued but soon taken as prisoners of war by the Japanese and sent to a camp in Saipan. Noonan is beheaded and Earhart dies in 1939 from malaria or dysentery.

Theory Four: Earhart and Noonan make it to Howland Island as planned and are eaten by cannibals.

Theory Five: Earhart was an American spy sent to gather information on the Japanese ahead of World War II.

Theory Six: Earhart and Noonan are unable to locate Howland Island, and head toward their 'contingency plan'. After a ten hour journey back toward the location they came from, they crash in the jungle of East New Britain Island, in what is now known as Papua New Guinea.