I am not sure the luck comes from finding a bottle or getting away with telling this story for so long. However, there is a story on the Herald Sun website which says,
… Reg Cohen, who had enlisted in the army and found himself on a steamer pulling out of Albany heading for Gallipoli. The year was 1915.
Reg wrote a letter to his sister, Esme, put it in a bottle and tossed it overboard as the boat pulled out of Albany, at the bottom end of Western Australia.
Thirty-one years later, Esme was walking around the beach at Port Melbourne, as she did ever day [sic], when she found the bottle and the letter.
I think these days it is not that difficult to get a message to somebody who lives in Port Melbourne. It seems like every day people happen to bump into eachother on Bay Street, but to get a particular message through people tend to send off an email.