Cindy Low, Kate Goodchild, her brother Luke Dorsett and his partner Roozi Araghi died in October 2016 when a water pump on the Gold Coast theme park's Thunder River Rapids ride malfunctioned.

In delivering his inquest findings on Monday, Coroner James McDougall said Dreamworld presented itself as a modern, world-class theme park, but its "frighteningly unsophisticated" safety procedures were "rudimentary at best".

Mr McDougall said there was a "systemic failure" by Dreamworld in all aspects of safety, and there had been no thorough engineering risk assessment of the ride in the three decades it was open to the public.

He referred parent company Ardent Leisure to the Office of Industrial Relations for possible prosecution under workplace laws.

The company could face fines of up to $3 million, with individual executives facing up to $600,000 and five years' jail.

External engineer, Tom Polley, has also been referred to the Board of Professional Engineers for failing to properly inspect the ride.

"I find that shoddy record-keeping was a significant contributor to this incident ... (and) contributed to the masking of the real risk of the (ride)," he said.

More than a hundred people packed the Brisbane Coroners Court to hear the long-awaited findings.

All four victims died after being flung into a mechanised conveyor when their raft collided with another and partially flipped.

The malfunction was the third that day and the fifth in a week, and no automated shutdown function was installed despite recommendations.

Ms Goodchild's 12-year-old daughter and Ms Low's 10-year-old son survived the incident.

Ms Low's husband Mathew was scathing towards the theme park operators.

"Today's findings have proven what was glaringly obvious. Dreamworld was a catastrophe waiting to happen because of their barefaced disregard for safety and maintenance," he said in a statement.

"It is clear that ride maintenance, safety and emergency procedures, and a general negligent corporate culture toward training and safety caused the death of our loved ones."

Ms Low's brother Michael Cooke spoke bitterly about the day his sister died saying his family had struggled to cope.

"I arrived to a nightmare, my mother was hysterical," he said.

"Dreamworld cares about saving face and the bottom dollar."

Ms Goodchild and Mr Dorsett's mother Kim Dorsett spoke of her grief, saying her greatest regret was not being there for her children on the day they needed her most.

"The easier part was burying them, the harrowing part is living without them," she said wiping tears from her cheek while speaking in court.

Following the tragedy Queensland introduced new safety regulations for amusement rides, including mandatory major inspections of rides by qualified engineers every 10 years and improved training for ride operators.

The state also tightened workplace health and safety prosecution laws.

Ardent Leisure issued a statement extending its sympathies to the families and friends of the victims of the tragedy.

It says it will create a memorial garden at the theme park to honour the victims and reaffirmed its commitment to implement the coroner's recommendations relating to Dreamworld operations.

Ardent chairman Gary Weiss and chief executive John Osborneeach read a statement at a press conference on Monday afternoon, expressing sympathy for the families but neither took questions.

The pair also failed to discuss the prospect of prosecution or Ardent's share price collapse on Monday by as much as 18.1 per cent to a near two-month low of $1.155 in morning trade.

Australian Associated Press