I've never been able to work out how my great great grandfather William Rich (born abt 1832, Bridgewater, Somerset, UK; died 1927, Willoughby, NSW, Aust) got to Australia.
I knew from his death notice that he was a Crimean War veteran, and he presumably arrived in Australia after he had completed his war service. It is just about impossible to find Crimean War records, but today I found that there were a number of William Richs who served in the merchant navy, and some merchant navy ships did indeed serve in the Crimean War.
There is even a merchant navy listing for a William Rich, born in Bridgewater. His register ticket number was 56694. Unfortunately, I can only find a listing in the index for him, but there does not appear to be an actual record of his service available. So I may never know if it was him in the merchant navy, but it doesn't seem so far fetched to think that he may have been working on a ship when he came to Australia, and stayed.