Nearly 700 complaints about unacceptable behaviour – including sexual misconduct, bullying and harassment – within the Royal Australian Navy Fleet Command have been reported in the past two years.
More than a quarter of the reports in the past year were substantiated.
The data was revealed during a hearing at the Royal Commission into Defence and Veteran Suicide in Perth on Monday.
According to an internal Fleet Command Board report, there were 342 complaints made in the 12 months prior to February 2023, and a further 348 in the year before that.
Fleet Command is responsible for the command, operations, training and force generation of all ships, submarines, aircraft squadrons, diving teams, and shore establishments of the Royal Australian Navy.
The inquiry heard 27 per cent of the unacceptable behaviour incidents in the past year were substantiated.
Most senior ranks, including captain and commodore, were among the respondents of substantiated unacceptable behaviour complaints.
More than two dozen complaints against lieutenants and lieutenant commanders were also substantiated.
"Unacceptable behaviour – even if it's a complaint that's not upheld – is unacceptable," Shore Force Commander Commodore Heath Jay Robertson told the inquiry.
"It is absolutely to the disadvantage of our ability to fight it and when it's seen … it's important, because perception is reality for that person making the complaint and there was probably still not appropriate behaviour that's occurred.
"So we need to get on top of it."
No 'consistent theme' in suicide-related incidents: captain
During his evidence at the same hearing, former commanding officer of naval base HMAS Stirling Captain Gary Lawton revealed there were about 11 suicide-related incidents each year within his command.
The commission was provided with the total number of suicide-related incidents at HMAS Stirling between January 2017 and January this year, but this data was not released to the public.
The inquiry was told there were no deaths by suicide within the command of about 2,000 people during Captain Lawton's two-and-a-half-year tenure, which ended recently.
Captain Lawton said there was no formal process of collating data around suicide-related incidents within his command.
He said he did not believe systemic issues were a contributing factor but admitted there was no effort made to analyse the incidents for trends or themes.
"I don't think we've got people with the skill sets to actually investigate those issues," Captain Lawton told the inquiry.
"There's an issue there, clearly. How much of it is related to the direct work pressures that people experience? I can't say, there doesn't seem to be a consistent theme to me."
More focus needed on suicide prevention
During Tuesday's hearing, Deputy Secretary of the Defence People Group Justine Greig admitted there needed to be more focus on suicide prevention within Defence.
The commission looked at a report analysing individual reports of 57 deaths by suicide of Australian Defence Force (ADF) members, which the ADF was notified of between 2016 and 2022.
The analysis found it took on average 575 days for the inspector-general of the ADF to release a report into the death after the member had died.
The inquiry heard the analysis report did not find any significant trends with unacceptable behaviour, sexual misconduct or the military justice system.
Mental health problems and relationship breakdowns were listed as the most prevalent likely factors contributing to a member's suicide.
The analysis noted that 17 reports included a finding that the death arose out of or in course of the members service in the ADF, but only five of those reports contained actionable recommendations.
"I thought it was an interesting point that could benefit from further consideration," analysis report author Anneliese Hilder told the inquiry.
"I found it interesting because [those reports] came to a conclusion that there was a defence nexus, yet they didn't find – apparently didn't find any gaps or anything different that the defence could have done in that circumstance."
The royal commission's Perth hearings will conclude on Thursday.
The Department of Defence has been contacted for comment.
