The Bora-class hoverborne guided missile corvette of the Russian Navy, also bears the NATO class name Dergach, is one of the few types of military surface effect ship built solely for marine combat purposes, rather than troop landing or transport. Its designation in the Soviet and Russian navies is Project 1239; the first vessel produced under this designation was Sivuch, which was later renamed Bora. It is one of the largest combat sea vehicles with catamaran design.