Knowles was at times beset by problems with discipline aboard his ships, often due to large proportions of raw recruits and untrained seamen.

[2] He joined in navy in 1768 as a midshipman aboard the 36-gun frigate HMS Venus, which was then serving in the English Channel under the command of Captain Samuel Barrington.

[5][4] “..the book as a whole seems an astonishing achievement for a young man of twenty-four - even with Nelson’s captaincy at the age of twenty in mind…..all mark Knowles as a true innovator".

[3][4] He returned to active service again during the summer of 1778, and was present with Barrington's fleet at the Battle of St. Lucia on 15 December 1778, serving aboard Commander James Richard Dacres's 18-gun HMS Ceres.

[4][7] In May 1779 he was briefly ordered to be master and commander of the storeship HMS Supply, but had returned to the Prince of Wales by 6 July, when he took part and was wounded in the Battle of Grenada.

[4][7] Knowles returned to England with Barrington in October 1779, and by December had joined Admiral Sir George Rodney's flagship, the 90-gun HMS Sandwich, as a volunteer for the Relief of Gibraltar.

[4][7] Knowles went on to serve in a highly active role in the defence of British trade in the Mediterranean, engaging privateers and escorting convoys.

At one point he was briefly blockaded in Menorca, where he fell ill.[4][7] He was eventually able to escape to sea in January 1781, and was based out of Gibraltar until his return to England in April 1782.

[4] On his arrival he was accused of piracy and murder, but was able to clear his name, returning to Gibraltar aboard HMS Britannia to resume command of the Porcupine.

[4][7] He became senior naval officer there on the departure of Sir Roger Curtis, until returning to England once more in command of the 74-gun Spanish prize HMS San Miguel.

Knowles passed this latest information on to Lord Howe, who moved his Channel fleet to intercept it, setting in motion the events that would lead to the Glorious First of June.

[4] Typhus and 'the itch' were rampant, on the ship's return to port she had to be scrubbed with lime water and fumigated with vinegar, while 100 men were discharged to the hospital.

[9] The following morning both Knowles on the Goliath, and James Whitshed on HMS Namur had observed the vulnerable situation that the Santísima Trinidad was in, and attempted to signal this to Jervis.

[2][9] He was promoted to Rear-Admiral on 14 February 1799, two years to the day after the Battle of Cape St Vincent, a Vice-Admiral on 24 April 1804 and a full Admiral on 31 July 1810.

His posthumous reputation is suggested, not by his rocky relationship with Jarvis but, by the words of a simple sailor who served under him at the Battle of Cape St Vincent: “ Not a man on board but would have bled for Sir C. H. Knowles.