Also living at Norwich was his aunt, Dame Sarah Martineau (1725–1800) who wrote comforting letters to family members,[4] including her sister-in-law and niece – David's mother and sister respectively – concerning her nephew's well-being and death.

In April 1787 he was appointed master of Supply, part of the First Fleet that established British settlement in New South Wales.

[11] Blackburn joined Phillip's expedition in search of a better location for the settlement,[8] and describes Sydney Harbour as "excellent and extensive".

[10] He died of illness on 10 January 1795 at Royal Hospital Haslar, Gosport, Hampshire, England.

The whip, along with his papers and letters, remained as revered, precious objects of a celebrated seafarer in the Blackburn family's possession until the 1990s when they went under the hammer at Christie's, London where a South Australian dealer purchased the club/whip (along with a small cosh which Blackburn probably carried for self-defence).