In less than a minute the ferry lay on the bed of the harbour and 40 people were dead.

Yet despite three courts of inquiry and an appeal, no one was ever charged over what remains the worst maritime disaster to have occurred in Sydney Harbour.

Now the full story of the deadly collision has been properly researched and, for the first time, clear blame for the tragedy has been apportioned.

The chilling story of the collision and its unsatisfactory legal aftermath is told in Greycliffe: Stolen Lives by Steve Brew, complete with biographical details of the 40 victims of the tragedy.

One of those victims, 49-year-old widow Millicent Bryant, had been a long-time resident of Manly and the first female in Australia to obtain a pilot's licence.

At 4pm on Thursday, November 3, 1927, the passenger liner Tahiti left her berth at Darling Harbour, bound for San Francisco under the control of a pilot.

Fourteen minutes later the ferry Greycliffe left Circular Quay bound for Garden Island, Nielsen Park and Watsons Bay.

After stopping at Garden Island to pick up homeward bound workers from the naval base, the Greycliffe made her way towards Nielsen Park.

The Tahiti and the Greycliffe were now travelling on parallel but slightly converging courses.

The Greycliffe was the slower vessel and was in front of the Tahiti, which was gaining on the ferry but which was bound by law to keep clear of the ferry.

Had both vessels maintained their normal courses, all would have been well.

But as the Greycliffe neared Bradleys Head she veered unexpectedly into the path of the Tahiti.

Despite the liner sounding her ship's horn and her engines being thrown full astern, a collision was inevitable - there was no time for the liner to change course or for the ferry to get out of the way.

The Greycliffe was doomed.

When the bow of the Tahiti struck the Greycliffe, it cut into the ferry, pushed it forward and rolled it over, then broke it in two.

In less than a minute the ferry had gone to the bottom, leaving only a mess of flotsam and dozens of struggling survivors on the surface.

Boats of all shapes and sizes rushed to the scene of the collision, their occupants struggling to comprehend the enormity of what they had witnessed.

The survivors were rescued and most were taken to the Man o' War Steps for treatment.

Forty people died in the disaster, most of them residents of Vaucluse and Watsons Bay.

Sydneysiders were shocked by the tragedy.

One of the victims was Vaucluse resident Millicent Bryant, who had lived at Manly for many years and whose three sons had all been born at Manly.

In March 1927, eight months before her death, Mrs Bryant had become the first woman in Australia to obtain her pilot's licence and she was about to begin an advanced flying course.

At the time of her death, Mrs Bryant's oldest son, George, was in England, and another son, John, was in Tasmania, so neither was able to attend the funeral.

It was left to Mrs Bryant's youngest son, 19-year-old Bowen, to identify his mother's body and to lead the family at the funeral.

Mrs Bryant was buried in Manly Cemetery, following a service by Rev Ebbs of St Matthew's Church on The Corso, and the burial was accompanied by a flyover by five aircraft.

Piloting one of the aircraft was Mrs Bryant's flying instructor, Captain Leggett, who descended to 50m above the grave and dropped a wreath of blue delphiniums and red carnations.

Even before the last of the victims' bodies had been retrieved from the harbour, the investigations began.

The Court of Marine Inquiry and the Coroner's Inquest began on the same day, followed soon after by an inquiry in the Admiralty Court and a subsequent appeal against that court's findings.

What stood out from the different courts were their different findings.

The Court of Marine Inquiry found the Tahiti to blame; the Coronial Inquest found both vessels to blame and the Admiralty Court found the Greycliffe more at fault than the Tahiti.

An appeal against the Admiralty Court's finding was rejected and only strengthened the case against the Greycliffe.

While no case of criminal negligence was laid against the two men at the centre of the collision, the ferry's master and the liner's pilot, the disaster spelled the end of both men's careers.

Central to all of the inquiries was whether the liner Tahiti has been speeding and whether the ferry Greycliffe had veered from her course.

From the evidence presented to the courts it was clear that both had occurred.

But author Steve Brew argues that the speed of the Tahiti was only a contributory factor in the collision - it did not cause the ferry to change course into the path of the liner.

The crux of the matter, he argues, is that the ferry had veered off course.

Irrespective of whether the ferry master knew he was off course, whether he had turned the helm or whether the course of the ferry had shifted due to a mechanical malfunction, it was still the ferry master's duty to know the position of his vessel and that of any other vessels in the vicinity.

Had the ferry maintained her normal course, the collision would not have occurred.