SMS Nix was the lead ship of the two-vessel Nix class of avisos built for the Prussian Navy in the early 1850s. After commissioning in 1851, Nix saw little activity, apart from short training exercises and cruises in the Baltic Sea, which were frequently punctuated with boiler fires. A dissatisfied Prussian Navy decided to sell both Nix-class ships. In 1855, the Prussians sold Nix to the British Royal Navy in exchange for the sail frigate Thetis, and was commissioned as HMS Weser. She saw action during the Crimean War at the Battle of Kinburn in October 1855, and thereafter saw little activity, being based in Malta. She was ultimately decommissioned in 1865, used as a harbor ship, and then sold to ship breakers in 1873.