According to the headstone transcription (taken in 1901), the four deceased "were unfortunately drowned by the upsetting of a boat" (this occurred just off Dawes Battery). The inscription also comments that the stone "was erected by a Lieutenant of the Bathurst who was upset with them". This was Lieutenant Roe. There is a note in the transcription which states that the headstone was relocated to La Perouse (i.e. Bunnerong Cemetery). ref # 568 . ref # 568 - Survey duties under Lt Philip Parker King. Boat incident in Sydney Cove including Lt. John Septimus Roe ( later Surveyor General of WA) who paid for their headstone. See also #16 James McMurtry & #17 Thomas Robinson
