The Melbourne ringleader of a “tinnie terror” plot to sail from Queensland to help overthrow the Philippines government will spend up to seven years behind bars.

Islamic State sympathiser Robert “Musa” Cerantonio and five other men plotted in 2016 to sail a seven-metre fishing boat off the Queensland coast, with plans to encourage others to overthrow the southern Philippines government and establish sharia law there.

Cerantonio pleaded guilty to engaging in conduct in preparation for hostile activities.

On Friday, the supreme court justice Michael Croucher ordered him to serve at least five years and three months in prison before being eligible for release on parole. He has already spent nearly three years in custody.

Croucher said Cerantonio’s role in sharing his “putrid ideas” was deserving of a greater punishment than the other men who were subordinates and influenced by him.

His co-accused – Murat Kaya, Kadir Kaya, Paul Dacre, Antonio Granata and Shayden Thorne – have each already been jailed for periods up to four years.

Croucher said Cerantonio was obviously intelligent. “He intended to use his considerable gifts for evil, not for good.”

He was not satisfied that Cerantonio had renounced his extremist beliefs since his arrest in May 2016. The court has previously been told the 34-year-old was raised Catholic but became an Islamic “wunderkind” online and across TV and radio.

Cerantonio’s lawyer, Jarrod Williams, said his client did not fit the typical role of an extremist, and enjoyed music by AC/DC, Cold Chisel, Johnny Cash, Paul Simon and Rammstein.

“This is a man who doesn’t always fit the profile of an Islamic extremist,” he said.