Vigilant-class gunvessel
 The Vigilant-class gunvessel of the Royal Navy was an enlarged version of the Arrow-class gunvessel of 1854. Both classes were designed for shallow-water operations in the Baltic and Black Seas during the Crimean War. Fourteen of the class were completed but were ready too late to take part in that conflict. Cormorant was sunk in action at the Taku Forts Osprey was wrecked on the coast of Africa in 1867 and the rest were all sold during the 1860s with Sparrowhawk lasting until 1872.