Change to Zuikaku Beam For ships that share the same construction times (often sister ships), it's unknown which ship will be built until they're finished. Players are often vexed if the more readily obtainable ship is built after repeated attempts, and wonder if some outside force has converted the ship into the more common variant. Reversal of "Change to Mutsu Beam" as Zuikaku is the rarer of the Shoukaku sisters who share a unique timer.