The Neptune-class amphibious assault ships are designed to land forces on hostile shores, and they are the largest vessels of this type in service anywhere in the world. Originally designed by the Shinra Republic, it has found widespread use in the Canissian Royal Navy, the Imperial Byzantine Navy, the Langley Navy, the PeZookian Navy, the Royal Emmerian Navy, the Tian Xia Navy, and the Wilkonian Imperial Navy. There are 6 distinct subclasses currently in use: the original steam-powered version, the nuclear-powered version (also known as the Neptune-class), the gas turbine-powered Fujian-class, the aviation-focused Shaanxi-class, the lengthened Chatham Isle-class, and the angled deck Graf Gustaf-class.