The development of marine current turbine arrays depends on the understanding of the interaction effects that exist between turbines in close proximity. Moreover, the ambient turbulence intensity also plays a major role in the behaviour of tidal turbines. Thus it is necessary to take ambient turbulence into account when studying interactions between several turbines. In order to highlight these interaction effects, experiments were carried out in the IFREMER flume tank of Boulogne-sur-mer (France). These experiments focused on elementary interactions between 3-bladed horizontal axis turbines. This data-set provides the experimental measurements obtained for three configurations with two ambient turbulence intensity rates. The measurements are divided in terms of turbine performances and flow velocity measurements.  For the flow velocity measurements, a special care was taken in the zone of interest, i.e. where the turbine wakes are interacting. For the turbine performances, only the downstream turbine parameters, e.g. torque, rotation speed and drag force, are recorded in order to quantify the upstream turbine row masking effect. These measurements are provided so that to serve as a benchmark test case for numerical validation.