By Dominic Giannini in Canberra

The new chief of the Australian Defence Force will get many more chances to fulfil his childhood dream of “messing about in boats” as he stepped into the role on Wednesday.

Vice Admiral David Johnston, who spoke at a changing-of-command parade in Canberra, is taking over the military as it focuses on expanding naval to counter threats in the Pacific region, following a major defence review.

“From my childhood as my wife described as ‘messing about in boats’, I have lived all my life in the ADF,” he said.

“I have witnessed the extraordinary contribution ADF members make in war like operations, peace keeping and protecting our border and engaging with our partners.”

A landmark review into the defence force recommended it refocus on being able to project its firepower deeper into the Pacific to meet the rise of China, with new nuclear powered submarines being a core element.

Vice Admiral Johnston said his career moves around the the Indo-Pacific and Asia would be useful in his new role.

“This experience greatly aids my understanding of our history and role in the region,” he said.

A review of the navy’s surface fleet led to a decision by Defence Minister Richard Marles to scrap a planned build of larger ships to make room for a bigger fleet.

The number of navy warships is set to increase from 11 to 26 by the mid-2040s and the fleet will include remote-controlled vessels as the military places a greater emphasis on drones.

The vice admiral took over from Gen Angus Campbell after serving as the vice chief.

Gen Campbell served in the role for six years.

Air Marshal Rob Chipman has taken over the role of vice chief.

“It’s a profound responsibility that I accept with humility and resolve,” he said.

The scale of investment in military technology was “simultaneously unsettling and imperative” during a precarious time in the Indo-Pacific, he said.

“It’s time now, to redouble our efforts and deliver the combat strength Australia needs to deter military adventurism and preserve a stable balance of power in our region.”