Abstract : Progress is reported on laboratory measurements of gravity wave/ critical layer interactions. Previous results have been reported for the interactions of single monochromatic waves propagating in a stratified fluid with a vertical velocity shear. The new results presented here are for two monochromatic forcing waves, each propagating with a different phase speed. Thus, the critical layer for each wave is distinct in the vertical. The results for the two-wave case are compared to similar results for the one-wave case. In the one-wave case, only weak overturning appeared in the upper part of the tank for interaction times longer than about 13 minutes, and regular, periodic turbulence was observed in the lower part of the tank. In contrast, in the two- wave case, sustained overturning was observed in the upper part of the tank and packets of turbulence were seen in the lower part of the tank. Velocity profiles are currently being examined to attempt to understand these observed differences. Other improvements in the hardware and software of the facility are also reported, and plans for the coming year are discussed. Gravity wave, Critical layer, Internal wave, Stratification, Shear, Turbulence.