Genealogy Chat

Just thought I would ask as you lot are so clever on here... Does anyone know how I would go about a) Finding the record of and b) Ordering a copy of, my Great Grandfather's death certificate? His name was Frederick Waters. He was born in Chatham Kent in 1858. After his first wife died, he married again to Emma Hogben b. c1871 (previously Emma Ralph - she'd also been married before). That marriage was in 1909 in Faversham Kent. They had a daughter Marjorie E Waters, born in 1911. On 02.02.1912 they boarded the Otranto bound for Freemantle Australia. After this, I've been unable to trace them, other than Frederick's death at Perth in 1926. There is a letter from my Grandmother (Frederick's older daughter) to the war office, about her father's death, where the War Office have obviously asked about his second wife, and in her reply, my grandmother states that Emma left Frederick and moved to China. Now I'm not sure if this is true or if she just said it to get his personal posessions and any pay he was due. I've been searching to try and find any info about them for nearly a year now and keep hitting a brick wall as I am not that clued up on where to look, I'm pretty basic when it comes to searching, and have used Genes, Ancestry and the LDS site, but not found anything from any of them. Can anyone give me any ideas where I might try looking next ? Thanks in advance! Gerry