Early career (1854–1869)
Fisher's father ultimately aided his entry into the navy, via his godmother Lady Anne Wilmot-Horton, widow of the governor of Ceylon to whom William Fisher had been Aide-de-camp. She prevailed upon a neighbour, Admiral Sir William Parker (the last of Nelson's captains), to nominate John as a naval cadet. The entry examination consisted of writing out the Lord's Prayer and jumping naked over a chair. He formally entered the Royal Navy on 13 July 1854, aged 13, on board Nelson's former flagship, Victory, at Portsmouth. On 29 July he joined HMS Calcutta, an old ship of the line. She was built of wood, in 1831, with 84 smooth-bore muzzle-loading guns arranged on two gun decks, and relied entirely on sail for propulsion. She had a crew of 700, and discipline was strictly enforced by the "hard-bitten Captain Robert Stopford". Fisher fainted when he witnessed eight men being flogged on his first day.
Calcutta participated in the blockade of Russian ports in the Gulf of Finland during the Crimean War, entitling Fisher to the Baltic Medal, before returning to Britain a few months later. The crew was paid off on 1 March 1856.
On 2 March 1856, Fisher was posted to HMS Agamemnon, and was sent to Constantinople (now Istanbul) to join her. He arrived on 19 May, just as the war was ending. After a tour around the Dardanelles picking up troops and baggage, Agamemnon returned to England, where the crew was paid off.
Promotion to midshipman came on 12 July 1856 and Fisher joined a 21-gun steam corvette, HMS Highflyer, part of the China Station. He was to spend the next five years in Chinese waters, seeing action in the Second Opium War, 1856–1860. The Highflyer's captain, Charles Shadwell, was an expert on naval astronomy (subsequently being appointed a Fellow of the Royal Society in 1861) and he taught Fisher much about navigation, with spectacular later results. When Shadwell was replaced as captain following an injury in action, he gave Fisher a pair of studs engraved with his family motto "Loyal au Mort", which Fisher was to use for the rest of his life.
Fisher passed the seamanship examination for the rank of lieutenant, and was given the acting rank of mate, on his nineteenth birthday, 25 January 1860. He was transferred three months later from the steam frigate Chesapeake to the screw corvette Pearl as an acting lieutenant. Shortly afterwards, Fisher had his first brief command: taking the yacht of the China Squadron's admiral—the paddle-gunboat HMS Coromandel—from Hong Kong to Canton (presently Guangzhou), a voyage of four days.
He was transferred, on 12 June 1860, to the paddle-sloop HMS Furious where he saw sufficient action to add the Taku Forts and Canton clasps to his China War Medal. Furious left Hong Kong and the China Station in March 1861 and, after a leisurely voyage home, paid off her crew in Portsmouth on 30 August. Captain Oliver Jones of the Furious was entirely different from Shadwell: Fisher wrote there was a mutiny on board within his first fortnight, that Jones terrorized his crew and disobeyed orders given to him. For his part, by the end of the tour, Jones was impressed by Fisher.
In November 1861, Fisher sat his final lieutenant's examination in navigation at the Royal Naval College at Portsmouth, passing with flying colours. He had already received top grades in seamanship and gunnery, and achieved the highest score then attained under the recently introduced five-yearly scheme, with 963 out of 1,000 marks in navigation. For this, he was awarded the Beaufort Testimonial, an annual prize of books and instruments; but in the meantime he had to wait around, unpaid, until his appointment came through officially.
From January 1862 to March 1863, Fisher returned to the payroll at the navy's principal gunnery school aboard HMS Excellent, a three-decker moored in Portsmouth harbour. During this time, Excellent was evaluating the performance of the "revolutionary" Armstrong breech-loading guns against the conventional Whitworth muzzle-loading type. During free afternoons Fisher would walk the downs, shouting to practise his command voice. He spent 15 of the next 25 years in four tours of duty at Portsmouth concerned with development of gunnery and torpedoes.
In March 1863, Fisher was appointed Gunnery Lieutenant to HMS Warrior, the first all-iron seagoing armoured battleship and the most powerful ship in the fleet. Built in 1859, she marked the beginning of the end of the Age of Sail and, coincidentally, was armed with both Armstrong guns (breech-loading) and Whitworth guns (muzzle-loading). Fisher noted he was popular amongst his brother officers because he frequently stayed on board when others went ashore and could take duty for them.
Fisher returned to Excellent in 1864 as a gunnery instructor, where he remained until 1869. Towards the end of his posting he became interested in torpedoes, which were invented in the 1860s, and championed their cause as a relatively simple weapon capable of sinking a battleship. His expertise with torpedoes led to his being invited to Germany in June 1869 for the founding ceremony of a new naval base at Wilhelmshaven, where he met King William I of Prussia (soon to become German Emperor), Otto von Bismarck and Helmuth von Moltke the Elder. Perhaps inspired by the visit, he started preparing a paper on the design, construction and management of electrical torpedoes, the cutting-edge technology of the time.