This presentation outlines the evaluation of wake models for a tidal farm design tool by comparison to experimental data for multi-row arrays of 3-12 turbines. It provides information on the performance assessment of wave and tidal array systems, the primary objective, motivation, WindFarmer, TidalFarmer, scale testing, comparison with experiments, the inflow to second row of aligned turbines, inflow to third row of staggered, comparison to 3 row experiment and commercial launch at RUK.