A total of four ships of the Shokaku class were planned, but only two have been completed: the Shokaku (launched June 1939) and the Zuikaku (launched November 1939). The ships were very similar and differed mainly in the configuration of their anti-aircraft weapons.
The Zuikaku (Japanese: 瑞鶴 "Fortunate Crane") was laid down at Yokosuka Dockyard on 12 December 1937, launched on 1 June 1939. During the war she formed the 5th Aircraft Carrier Division with her sister ship. In December 1941, she took part in the attack on Pearl Harbor. In May 1942, it was damaged during the Battle of the Coral Sea by bombs and fell for further operations from first. In August 1942, she was involved in the Battle of the Eastern Solomon Islands, followed by the Battle of the Santa Cruz Islands in October. She participated in the Battle of the Phillipine Sea in 1944, in which her sister Shokaku was sunk by American submarine USS Cavalla. In October of 1944, Zuikaku participated in the Battle of Leyte Gulf, in which she, along with 3 light carriers, were to lure USN Fleet Admiral William "Bull" Halsey's fleet away from Leyte, leaving General Douglas McArthur's landing forces vulnerable to the IJN's battleships. She, along with the other light carriers, was sunk in what became known as the Battle of Cape Engano. In Forgotten Hope Secret Weapons the Shokaku and the Zuikaku are both ships of Shokaku-class. The difference is in the names; weaponry and models are the same. Instead of the main game very unrealistic weaponry with Bofors anti-aircraft guns each position now receives 4 12.7-mm guns and 6 25 mm, so they are much better prepared against medium and heavy bombers. However, guns can fire only anti-aircraft shells, so bombardment of enemy ships remains ineffective. Also, those ships somewhat more detailed textures comparing to original game.
Since aircraft in FHSW usually resupply back at the airfield or aircraft carrier after a bomb attack, carriers are even more important than in the main game. They should therefore always be in the vicinity. So, for example, bombers can realod faster and you obtain a tactical advantage.