  Smooth real cubic surfaces are birationally trivial (over $\R$) if and only
if their real locus is connected or, equivalently, if and only if they have two
skew real lines or two skew complex conjugate lines. In such a case a
parametrization over the reals can be given by cubic polynomials. In this short
note we provide a simple geometric method to obtain such parametrization based
in an algorithm by I. Polo-Blanco and J. Top \cite{Po-Top}.
