Eduard Karl Emanuel von Jachmann (2 March 1822 – 21 October 1887) was the first Vizeadmiral (vice admiral) of the Prussian Navy.

During the Second Schleswig War in 1864, he commanded Prussian naval forces in the Baltic from Arcona, and led a small squadron at the Battle of Jasmund on 17 March.

During the Franco-Prussian War of 1870–1871, he commanded the squadron of ironclad warships based in the North Sea, though his ships saw no action owing to engine difficulties.

He expected to be named the first Chief of the Imperial Admiralty in 1872, but he was passed over in favor of the Prussian Army General Albrecht von Stosch.

Jachmann retired to Oldenburg with his family, though he returned to naval affairs in 1878 following the accidental sinking of Grosser Kurfürst during a training cruise.

[1] In early 1843, as the Prussian Navy looked forward to the completion of the corvette SMS Amazone, it began searching for cadets at the Danzig navigational school to form the ship's crew.

By this time, Jachmann was the third highest-ranking officer in the Prussian Navy, behind only Prince Adalbert of Prussia and the Swedish captain Henrik Sundewall.

On the way back to Germany, Jachmann had been instructed to investigate Patagonia as the site of a possible German colony, but he ignored the command, citing the poor condition of his ship after the long voyage to East Asia, and in particular after a severe storm had badly damaged her in South American waters.

On 17 March, Jachmann took his two ships and the armed paddle steamer SMS Loreley out to challenge the Danish blockade force.

[5] On 24 March 1865, with the fleet having returned to its demobilized, peacetime status, Jachmann was given command of the Marinestation der Ostsee (Naval Station of the Baltic Sea).

Later that year, Jachmann accompanied Roon aboard Loreley for a survey of the Jade Bay, where the naval base at Wilhelmshaven was planned.

Since the Austrian fleet was occupied with Prussia's ally Italy during the war, the Prussian Navy saw relatively little action; the only major operations were conducted in the North Sea, under the command of KzS Reinhold von Werner.

Jachmann included the large number of corvettes to bring pro-colonialist factions to support the plan, though he was himself ambivalent to colonial aspirations.

[16] At the start of the Franco-Prussian War in July 1870, Jachmann left Berlin to take command of the ironclad squadron based in Wilhelmshaven.

Work had not yet been completed on the fortifications outside Kiel and Wilhelmshaven; Jachmann ordered the acquisition of naval mines, a technology then still in its infancy, to help defend the German coast.

König Wilhelm and Friedrich Carl thereafter developed engine problems, preventing Jachmann from taking further offensive actions, for which he was publicly criticized.

As the highest ranking naval officer, Jachmann expected to be given the role as the Chief of the Imperial Admiralty, but General Albrecht von Stosch received the position instead.

Following the death of Prince Adalbert in June 1873 and the retirement of Roon the following October, Jachmann lost his most powerful friends, and Stosch largely ignored him.

Jachmann was appointed a member of the court martial that investigated the accident and the role of Carl Ferdinand Batsch—the captain of König Wilhelm and Stosch's protege.

[22] Jachmann retired to Oldenburg with his family, which included his wife Anna (whom he had married in 1852 in Trutenau near Königsberg), his daughter, and three sons.

Eduard appeared in public one last time on 18 May 1885, after Wilhelm I called on him to give the christening speech for the new corvette Arcona in Danzig.