State of detonation products is described by various types of equations of state. Jones-Wilkins-Lee (JWL) equation of state is widely used because of its simplicity. JWL equation of state contains parameters determined by the cylinder expansion test. We obtained these parameters through the method of characteristics applied to the configurations of underwater shock waves of cylindrical explosives. The numerical results obtained by using the JWL parameters determined by the underwater explosion test are compared with the experimental results. Good agreement between the numerical and experimental results is confirmed in the case of the ideal and non-ideal explosives.