Abstarct: Marine electric equipment recently has been entered to the industry and commerce and before the shipboard power system could provide only the small loads. With appearing this equipment, existence equipped power systems with high reliability, has become inevitable. No earthing is the features of this system that makes the relays fails to recognize the single phase to ground fault (SPTGF). If another SPTGF occurs, makes two phase fault occurs, in this case relays will trip and emergency loads are disconnected. As you know, failure emergency loads could cause danger to health personnel. In this paper, the purpose is to using wavelet transform and intelligent tools, SPTGF be detected in shipboard power system.