"Nymphe" was completed in time to see action during the Second Schleswig War with Denmark in 1864, at the Battle of Jasmund, where she was heavily engaged by a Danish steam frigate, being hit numerous times. "Medusa" entered service in 1867 and went on a deployment to the Mediterranean Sea in 1867–1868 and another cruise to East Asia in 1868–1871. During the Franco-Prussian War in 1870–1871, "Medusa" was blockaded in Yokohama, Japan, and saw no action. "Nymphe" was similarly blockaded in Danzig, Prussia, and she made a surprise nighttime attack on the French squadron, inflicting no damage but nevertheless convincing the French admiral that his ironclad warships were unsuitable for a close blockade of Prussian ports.