Able Seaman David Moffatt, a signalman in the navy reserve, was only 20 years old when he became one of the first Australians to give his life for his adopted country in World War I.

Born in Cornwall on May 1, 1894, he had emigrated to Australia with his parents and was working as an engineer in Sydney before being called up for active service.

He had lost his father when he was nine and his widowed mother died at the age of 61 in 1918.

Moffatt was a member of the joint army-navy force sent ashore near Rabaul to destroy a powerful German wireless transmitter on the morning of September 11, 1914. He had been serving aboard the Australian flagship, HMAS Australia.

The jungle path ran through difficult terrain and enemy snipers, concealed in the trees, took a heavy toll on the advancing force. By the time Moffatt was shot and badly wounded the medical officer, Captain Brian Pockley, had already been killed.

He was taken aboard HMAS Sydney for medical treatment but died early the following day.

Family records state the telegram, advising his mother Eva of his death, was hand-delivered by the Rector at Newtown.

"This was the first telegram he [the rector] had delivered in the war," the Clan Moffat website states. "This was very upsetting for Grandma Moffatt and she never recovered [from the loss]."

Able Seaman Jack Jarman, believed drowned when Australian submarine AE1 went down with all hands on September 14, 1914.

Jack Jarman, a country lad from Dookie in Victoria, was one of the Royal Australian Navy's finest sailors at the time of his death.

Aged 21 and a permanent member of the navy, he had been chosen to help sail the AE1 and AE2, Australia's first submarines, from England to Sydney in late 1913.

The two submarines entered Sydney harbour on Empire Day, May 24, 1914. They had broken all previous records for distances travelled by a submarine.

"The voyage had taken 83 days, 60 days of which were spent at sea," naval historian Dr Kathryn Spurling writes. "AE1 and AE2 had sailed 20,800 kilometres, 14,400 of it under their own power."

Less than three months after arriving in Australia the AE1 was on a war footing. It was dispatched north with the little task force charged with seizing German New Guinea and destroying wireless stations there.

While the operation was successful, the price was high. Seven Australians were killed in fighting on New Britain on September 11 and September 12.

Then, on September 14, came Australia's saddest news of the war to date. The AE1 had left Rabaul Harbour at 7am to go on patrol with HMAS Parramatta. The two vessels exchanged messages at regular intervals up until about 3.30pm. After that the submarine, and all the men aboard her, disappeared without a trace.

Jarman's service records state that he sported numerous tattoos including "Nellie over clasped hands, three horseshoes, heart and cross, ship in wreath, full rigged ship, shield and heart and a floral design on the left hand".

History does not record who Nellie was or what her relationship with Jarman had been.