Paul Douglas Frost was found guilty of 43 offences in June this year over his abuse of children under his care at a swimming school in Sydney's southwest between 1996 and 2009.
As the 48-year-old faced sentence in Sydney's Downing Centre District Court on Thursday, Judge Sarah Huggett said the coach "deliberately created a culture which facilitated his offending".
This included normalising talk of sex amongst the children and teenagers he was teaching, encouraging sexual activity both with and between students, and engaging in graphic acts in the school's changing room and storage room.
"Paul had built a culture of these types of things being normal," one of his victims wrote in a statement to the court.
"I know they seem a bit horrifying and strange now."
The victim said that as a boy he went along with discussing sexual matters openly with Frost as he wanted to be one of the "cool kids".
"I thought talking about that … was just what people did," he wrote.
"I thought it was normal."
Frost commented on one young student's "bubble butt", encouraged another to watch the sexually explicit TV show Sex Life and openly talked about the size of a boy's genitalia, the court heard.
He was arrested in September 2019 at his Sylvania home. Initially charged with only 10 offences, further allegations were raised as police investigated his crimes.
The 43 charges the swim coach faces sentence for include several counts of sexual intercourse with a child under his care, multiple charges of aggravated indecent assault of a person under 16 and grooming children for sexual activity.
Judge Huggett found Frost manipulated his victims and contrived opportunities for him to be alone with them.
She found each victim was a reliable witness who gave their evidence in court with "dignity and courage".
Frost, who was once a contestant on cooking show MasterChef, watched on by video-link from Shortland prison in Cessnock.
A previous trial had its jury discharged without a verdict after 16 days amid allegations of bullying and refusal to deliberate that a judge worried would taint the outcome.
The sentencing continues.
1800 RESPECT (1800 737 732)
National Sexual Abuse and Redress Support Service 1800 211 028
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