Abstract: This paper presents the derivation process of high pressure equations of state (EOS) of water based on Mie-Grüneisen equation and summarizes some commonly used EOSs for water, which are provided by commercial software. Hugoniot relations and Grüneisen parameters of the EOSs are developed according to the derived high pressure EOS. The Hugoniot relations are compared with the experimental data provided by the known LASL. The speed of sound just behind the shock wave of the EOSs is calculated and the influence of the Grüneisen parameters on the speed of sound is analyzed. The limitations of the EOSs are defined based on these comparisons and the analysis. The upper and lower limits of the speed of sound of the EOSs are also determined theoretically. Subsequently, spherical underwater explosion problems based on the EOSs are simulated using one-dimensional isentropic characteristic curve program. A TNT-based explosive is used in the simulations. Calculated results are obtained. Peak pressure versus scaled distance (R/R₀) plots of the EOSs are graphed, peak pressures from different EOSs are compared, and calculated errors are also analyzed.