Messages in a bottle written by two Australian soldiers a few days into their voyage to the battlefields of France during World War I have been found more than a century later on Australia’s coast.

The Brown family found the Schweppes-brand bottle just above the waterline at Wharton Beach near Esperance in Western Australia state on October 9, Deb Brown said on Tuesday.

Her husband Peter and daughter Felicity made the find during one of the family’s regular quad bike expeditions to clear the beach of trash.

Inside the clear, thick glass were cheerful letters written in pencil by Privates Malcolm Neville, 27, and William Harley, 37, dated August 15, 1916.

Their troop ship HMAT A70 Ballarat had left the South Australia state capital Adelaide to the east on August 12 of that year on the long journey to the other side of the world where its soldiers would reinforce the 48th Australian Infantry Battalion on Europe’s Western Front.

Neville was killed in action a year later. Harley was wounded twice but survived the war, dying in Adelaide in 1934 of a cancer his family say was caused by him being gassed by the Germans in the trenches.

Neville requested the bottle's finder deliver his letter to his mother Robertina Neville at Wilkawatt, now a virtual ghost town in South Australia.

Harley, whose mother was dead by 1916, was happy for the finder to keep his note.

Harley wrote “may the finder be as well as we are at present.”

Neville wrote to his mother he was “having a real good time, food is real good so far, with the exception of one meal which we buried at sea.”

The ship was “heaving and rolling, but we are as happy as Larry,” Neville wrote, using a now faded Australian colloquialism meaning very happy.

Neville wrote that he and his comrades were, “Somewhere at Sea.”

Harley wrote that they were, “Somewhere in the Bight,” referring to the Great Australian Bight.

That’s an enormous open bay that begins east of Adelaide and extends to Esperance on the western edge.

Deb Brown suspects the bottle didn’t travel far.

It likely spent more than a century ashore buried in the sand dunes.

Extensive erosion of the dunes caused by huge swells along Wharton Beach in recent months probably dislodged it.

The paper was wet, but the writing remained legible. Because of that, Deb Brown was able to notify both soldiers’ relatives of the find.

Harley's granddaughter Ann Turner said her family was “absolutely stunned” by the find.

Neville’s great nephew Herbie Neville said his family had been brought together by the “unbelievable” discovery.