Cavitation noise is strongly restricted by the Navy because this noise can be detected by the sonar systems installed on enemy ships to locate a ship. When cavitation is started, the high-frequency broadband noise increases modulated with shaft rotation and propeller blade passing frequencies. Therefore, the Cavitation inception speed (CIS) is typically detected using the Detection of envelope modulation on noise (DEMON) analysis to identify the underwater propeller noise. Since the CIS varies based on the ship’s condition and sea state, realtime CIS monitoring is required. In this paper, a CIS detection method that evaluates the acceleration on the hull adjacent to the propeller was proposed and verified through experimentation.