A rigging equipment diagnostic device includes a processor and a storage to store a program to be executed by the processor. The processor executes an equipment information collection process in which information on equipment fitted to a hull is collected, an attribute information acquisition process in which an attribute database to store attribute information including information on functions to be realized is searched and attribute information on equipment fitted to the hull is acquired, a requirement information acquisition process in which requirement information is acquired by searching a requirement database that stores requirement information necessary to realize functions corresponding to respective attribute information, a function determination process in which a realizable function and an unrealizable function are determined by comparing equipment information and requirement information, and a function information provision process in which the determination result is provided.