In this paper, direct numerical simulation is used to study the interaction between turbulence and a free surface. The configuration is original due to the fact that a random force generates turbulence in the vicinity of a plane parallel to the free surface. Turbulence is therefore statistically steady and nearly isotropic at some distance of the surface. A detailed description of the flow is provided, including second-order statistics and full Reynolds-stress budgets. It is shown that the results obtained in this configuration can help the understanding of intercomponent energy-transfer mechanisms.