When Acting Sub Lieutenant Harry Farthing began Maritime Warfare Officer Course 07 (MWOC07), the end felt a long way away.

But the Navy officer from Lilydale in Victoria's Yarra Valley graduated at HMAS Watson with 31 of his classmates on December 10.

The training, with four phases spanning two years, combines theoretical and practical preparation and assessments, enabling the officers to achieve their maritime warfare officer (MWO) professional qualification.

The MWOs will go on to consolidate their training at sea as an officer of the watch before starting specialist training in their chosen field.

"The course is long and intense at times, and you have to stay motivated, but working alongside your mates, all going through the same, and a good chain of command helps you find the final drive you need to finish strong," Acting Sub Lieutenant Farthing said.

"For me, Phase 3 on board HMAS Larrakia was a stand-out.

"We experienced extreme winds and monsoonal rain.

"I had to time it so I could take bearings through the bridge door window between the ship rolling.

"That was a great moment."

Taking bearings and other mathematics' functions are pivotal to a MWO - it's an area where science, technology, engineering and maths (STEM) are utilised within Navy.

"We use maths all the time on the bridge as an officer of the watch," Acting Sub Lieutenant Farthing said.

"It's funny as I remember being back at high school, sitting in my classroom, wondering why all this maths is relevant and when would I ever need trigonometry.

"I have certainly learnt my lesson now."

The role of a MWO is challenging and diverse, and brings a host of opportunities in a number of specialisations, something that interested Acting Sub Lieutenant Farthing, who is keen to pursue a career as a principal warfare officer.

"It is such a big role with so many ancillaries, responsibilities and processes - more than I could have imagined," he said.

"I am not sure what I expected, but I know it was the right choice for me.

"It's a unique role with a long career continuum that gives me great leadership experiences, responsibilities, life skills and amazing opportunities to travel.

"I have aspirations to become the commanding officer of one of the new nuclear submarines, so I am really keen to see where this career takes me."