The research focuses on cyclic collisions of water droplets with a solid surface of titanium alloy Ti6Al7Nb in varying environments between the nozzle and the impacted surface. The source of repeated impacts is an ultrasonically driven pulsating water jet. Each experimental run consisted of repeated droplet impacts at a starting frequency of 20 kHz concentrated on a single point with variance in exposure time from 1 to 10 s with 0.5 s increment. Two environments were used as the medium between the nozzle and the impacted surface, i.e., air and water. Differences in erosion effect under atmospheric and submerged conditions were followed regarding maximum erosion depth and removed volume. The droplet attenuation due to interference of the water jet with the water environment had detrimental effects on the maximum erosion depth achieved, reaching only 10 to 6 % compared to atmospheric conditions. A similar situation has been observed in the case of volume removed.