According to an article in 1934 with information supplied by his great grandson, John Inches first came to the colony with Lachlan Macquarie on the H. M. store ship Dromedary in 1809, Mr. Samuel P. Pritchard being commander of the ship. 
H.M. Ships Hindostan and Dromedary with Governor Macquarie on board, sailed from England on 3 May 1809. The 1st Battalion of Macquarie's own regiment, the 73rd Regiment of Foot came on both ships.
Elizabeth Macquarie, on board the Dromedary, kept a journal throughout the voyage and although there is no mention of John Inches in her journal, she does mention Commander Pritchard several times, particularly on 27 November when he became ill with acute rheumatism and was attended by the doctor -
as for the Doctor he sends for him at any hour of the night which strikes his fancy, and constantly thro' the day; but the worst of it is he can neither say nor do any thing to please him. 
Surgeon on the Hindostan was Joseph Arnold, a contemporary of John Inches.
Ensign Alexander Huey kept a journal during the voyage and after arrival. An extract of the journal can be found at The Garrison Gazette - (Extracts from the Journal of Ensign Alexander Huey on the Voyage of the 73rd Regiment of Foot to Sydney in 1809 (National Library Npf 910.4 HUE)
Naval history show that John Inches was still appointed to the Dromedary in the year 1811
He married Mabella Ann Ovey, youngest daughter of Commander Samuel P. Pritchard at Chalton Church in 1812, the year before her father passed away.
John Inches was appointed to the Barham in 1813. He was in the Navy List of Medical Officers in 1814.
He was employed as surgeon-superintendent on four convict ship voyages to Australia:
John Inches' eldest daughter Mabella married Robert Pringle of Carrington Park in August 1837 while he was stationed at Port Stephens.
In April 1840 John Inches announced that he had moved to East Maitland where he intended to offer his services as a Surgeon and Accoucheur.
He is listed in the Sydney Herald in November 1840 as a Retired Officer making a land purchase of 1280 acres, the deed being dated May 1840. After his death, the land was offered for sale in two portions and described as: adjoining the village of Kempsey near Commandant's Hill, Macleay River, being the land John Inches retired Royal Navy surgeon was permitted to purchase without competition in consideration of his services
According to the notice placed in the Sydney Herald, John Inches died on Thursday, 2nd December 1841 aged 55, much and deeply lamented by a numerous circle of friends and relatives. He was buried at St. Peter's Cemetery, East Maitland.
His wife Mabella Inches was residing with her daughter and son in law Mabella and Robert Pringle in 1847. Mabella Inches died in October 1857 at Balmain - the Funeral to move from Mrs. Dalyell's Darling Street residence.
Notes and Links
John and Mabella Inches' daughter Mabella Pringle died in Sydney in September 1860.