The vice chief of the Australian Defence Force has promised sweeping changes to ensure the safety of cadets after formally apologising to victims of child sex abuse within the organisation.

A mountain of inconsistent and incomplete policies around ADF cadet safety has created confusion and exposed children to harm, Vice Admiral Raymond Griggs says.

Giving evidence at the Royal Commission into Institutional Child Sexual Abuse on Thursday, Vice Adml Griggs said that both people and systems had let cadets down and placed others at risk.

"Your stories are changing the ADF and they have strengthened the resolve of the senior leadership of the ADF to stamp out abuse in all its forms, and in particular, child sexual abuse," Vice Adml Griggs said directly to victims and their families present.

"No one who pulls on the uniform of this country and no child who is under our care should ever have had happen to them what happened to you."

Over the past two weeks in Sydney, the commission has been told of humiliation and abuse endured by cadets, and brick walls faced in seeking redress and reparations.

It has also heard of attitudes towards policies and procedures ranging from ignorance to confusion or blatant disregard.

Vice Adml Griggs said the stories of victims were "tragic and transformational" and would help drive organisational change at the ADF.

Policies would be clarified and leadership structures tightened from July 1, he said.

"My interpretation of post-tomorrow is that we will be able to condense, streamline and thin out a lot of that policy which leads in my view, to confusion, which creates space and opportunity and increases risk," he said.

Also foreshadowed were much broader child safety reforms within the force to iron out inconsistencies across army, navy and air force cadet programs.

It had proved hard to shift attitudes among disparate groups of civilian cadet volunteers, who often held vastly different views of what constituted acceptable behaviour, Vice Adml Griggs said.

The close proximity in age between cadet trainees and instructors also poses a significant concern, with those involved often experiencing their sexually transformative years.

Vice Adml Griggs said enforcing periods of separation once trainees had graduated, or introducing probations for new instructors were two options being considered to mitigate any risks.

"It is a risk factor that I don't think is properly addressed at the moment," he said.

Age of consent laws across states and territories must also be harmonised to eliminate confusion, he said.

"I don't think we can stress how important (this is) ... I mean, it's critical."

Vice Adml Griggs sought to drive home the force's zero-tolerance approach to demeaning "hazing" rituals.

"Anything that damages people physically, sexually, psychologically is simply not acceptable," he said.

The hearing has been adjourned while final submissions are finalised.