[1] On 12 April 1866 the Admiralty announced that Lieutenant St John, in command of her Majesty's gunboat Opossum was promoted to Commander in consideration of the skill and judgement displayed in effecting the destruction of a large piratical force of 54 Chinese Junks, without loss in the attack and capture.

[2][3] St John became commanding officer of the sloop HMS Sylvia in November 1873.

[4] His memoir Notes and Sketches from the Wild Coasts of Nipon.

With chapters of cruising after pirates in Chinese waters were published in 1880 by David Douglas, Edinburgh.

[5] He was appointed commanding officer of the Central battery ship HMS Iron Duke in August 1885[6] and Senior Officer, Coast of Ireland Station in January 1892 before he retired in January 1895.