Platform motions of floating wind turbines generate periodic velocity fluctuations in the wake, but how these fluctuations synchronize with the motion of downstream rotors and modify their aerodynamic response remains poorly understood. In particular, experimental evidence of this wake–rotor coupling between multiple moving floating turbines is still lacking. A controlled wind-tunnel experiment was designed to isolate this mechanism using two 1:150 scale DTU 10 MW turbines arranged in tandem and subjected to prescribed harmonic surge motions. Motion reduced frequency (0.12–0.48) and the relative phase between the upstream and downstream turbine motions were systematically varied, while configurations with only one turbine moving were used to separate wake-induced and motion-induced contributions. Aerodynamic loads, equivalent aerodynamic damping, wake velocity fields, and farm-level power were analyzed. The upstream turbine motion generates coherent wake-velocity oscillations synchronized with the imposed surge, and the amplitude of velocity oscillations depends strongly on motion reduced frequency. When this periodically modulated wake interacts with the moving downstream rotor, its aerodynamic response becomes strongly dependent on the relative phase between the two turbine motions. In-phase motion produces the largest oscillations of downstream turbine thrust and the largest equivalent aerodynamic damping, whereas anti-phase motion reduces the amplitude of thrust oscillations and the damping to approximately half that of the upstream turbine. Across the investigated conditions, wake interaction systematically reduces the aerodynamic damping of the downstream turbine relative to the upstream turbine. In parallel, at the higher reduced frequency of 0.48, coherent wake pulsations also enhance wake recovery and increase power of the downstream turbine, whereas these effects are weaker at the lower reduced frequency of 0.12. These results provide experimental evidence that wake coupling between moving floating turbines is a phase-dependent interaction that affects aerodynamic loads, energy capture downstream in the farm and also the effective aerodynamic damping governing floating-turbine response.