Thank you all for your help!
A few updates...
William Nixon Horn, got his job in Chile as a chemist. He was originally from Greenock, Scotland. Violet joined him in to get married. After 2 and half years, she returned to see her mother in Scotland. Nearly 2 years later, she returned to William to find he had turned to alcohol. In 1901, he had "lost his situation" (I'm not quite sure exactly what this means). They sailed home, where he left Violet in Valparaiso, Chile. Once she had sailed home (1-2 months), she discovered he had already left and was apparently in Fremantle, Australia. Divorce granted in 1906.
The dates don't appear to add up. He apparently sailed in October 1901, she sailed in December 1901. She then discovered that he had sailed again in 1902 to Fremantle Australia, meaning that it would be unlikely for William to be George's father (he was born 3rd November 1903), even though he is listed on the birth certificate.
She could have lied to get the divorce granted, but that seems strange as there doesn't appear to be any other marriage or children.
I still can't find George in 1911.
I looked up the 1939 register, and George is listed with Margaret Ellen (how many times did she need to change her name!!!), alongside Violet Mary Booth (born 1932) and one that I cannot see. I assume this is my deceased Grandad, born 1935.
He has W.C next to his name (I do not know what this is?), and on his notes it says, Merchant Navy, although I have found no other records to go along with this.
