To study two-dimensional dispersive waves propagating over turbulent flows, a new and less restrictive fast waves approximation is proposed using a multiscale setting. In this ansatz, correlation lengths of the random small scale turbulence components can be considered negligible in the wave packet propagating frame. Still, the large-scale flow can be relatively strong, to significantly impact wavenumbers along the propagating rays. New theoretical results, numerical tools and proxies are derived to describe ray and wave action distributions. All model parameters can robustly be calibrated from the large-scale flow component only. We illustrate our purpose with ocean surface gravity waves propagating in different types of surface currents. The multiscale solution is demonstrated to efficiently document wave trapping effects by intense jets.