When radars operate in coastal or offshore environments, an undesired signal known as clutter appears as background in the measurements. The CA-CFAR detector is the classic solution for the detection of targets inside clutter, typically using a fixed value for its adjustment factor the entire period of operation. Using MATLAB, the author simulates the CA-CFAR response under amplitude samples from the classical sea clutter Weibull distribution. As a result, a relation between operating conditions (Weibull shape parameter) and the most efficient adjustment factor is obtained for various false alarm probabilities. Thus, the implementation of a new detector that achieves the adaptation to changing environments through the use of a variable adjustment factor is suggested. Note that sea environment is present in most radar scenarios both in military and meteorological applications.