Thanks Frances, I found William Heatherington last year thanks to yourself and the Manx Notebook. It was the mormon site on which I found his marriage to Margaret Crow but there was no mention of either sets of parents, I had hoped the parish record would hold more information.
I have found the marriage between Thomas Vondy and Ann Keerman mentioned in the notebook in Maughold in 1751 and they had a son William Vondy in 1767 but I am unable to make a connection between him and Wiliam who should have been born in 1821, according to the article in the Notebook.
The article states that 'Captain William was famous throughout the world as the oldest Manx passenger' so the story may have been in the newspapers around that time, I realise it is along shot but do you know of any Manx newspapers that the story may have appeared in and if so are they available to view.
Thanks again
Jason Heatherington