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 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 rubbish.

“We do a lot of cleaning up on our beaches and so would never go past a piece of rubbish. So this little bottle was lying there waiting to be picked up,” Deb Brown said.

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.