Air bubbles lower impact damage by breaking the surface of water and lowering density of water right near the surface. However small air bubbles at depth would have almost the same pressure as the surrounding liquid. So small bubbles would not lower considerably the pressure felt by a vessel unless there are so much of them as to considerably lower the density of the fluid all the way up to the surface, but this would rapidly exhaust the air reserves abroad the vessel.
There is a phenomenon, supercavitation, when a large bubble/cavity (filled with water vapor) encompass most of a rapidly moving through liquid body, considerably lowering friction drag. Parts of the body inside the bubble would feel only vapor pressure which would be considerably lower than the hydrostatic pressure of the surrounding fluid. However, for the formation of such cavity parts of the body would be exposed to a dynamical fluid pressures even higher than hydrostatic pressure at a given depth.
Current applications of supercavitation are projectiles, some propellers and supercavitating torpedoes, all operating at relatively small depths but potentially it is possible to apply the technology for deep underwater.