Water wave is a powerful source of energy; the problem is harnessing and making use of it. Wave power is a renewable, pollution-free and sustainable energy source. Since wave power varies with the wave period and the square of significant wave height, it is necessary to quantify the variations and statistical characteristics of these parameters with time. The aim of this study was to derive a general wave power equation that can be used in order to determine the mean and the standard deviation of the wave parameters using perturbation approach. The result of the study showed that Weibull probability distribution function is able to accurately simulate wave power. The wave power equation developed in this study is a general formula and can be applied at any desired region. The equation was then applied to five stations and it was seen that the perturbation approach yields better statistical values compared to results determined using classical statistical approach. This indicates that it is necessary to use perturbation approach to achieve optimum wave turbine design. (C) 2014 Elsevier Ltd. All rights reserved.