Abstract Electromagnetic VLF method can be used for the investigation of karstic cavities, which may often be seen along Turkey's southern coasts, the determination of these cavities which are naturally or artificaly filled or halfly¬filled by sea water, natural or artificial. This method is easier and more rapid than some other geophysical exploration methods. In this study, EM-VLF investigation method, which operates between 16 and 25 KHz as considered to be very low frequencies of electromagnetic spectrum, is used along with natural potential and direct current electric resistivity. During the studies, karstic cavities and fault systems related to these cavities and sea water were considered to be the most suitable model representing the region. In this model, structure is considered to be an excessively resistant medium and the fluid that fills the structure is considered to be a conductive medium.