  We present a series of optimal (in the sense of least-squares) curve fits for
the stiffened gas equation of state for single-phase liquid water. At high
pressures and (subcritical) temperatures, the parameters produced by these
curve fits are found to have very small relative errors: less than $1\%$ in the
pressure model, and less than $2\%$ in the temperature model. At low pressures
and temperatures, especially near the liquid-vapor transition line, the error
in the curve fits increases rapidly. The smallest pressure value for which
curve fits are reported in the present work is 25 MPa, high enough to ensure
that the fluid remains a single-phase liquid up to the maximum subcritical
temperature of approximately 647K.
