"Water" in the dream world is most often an archetypal image for feeling and emotion. To dream of an approaching tidal wave usually indicates an apprehension about the emotions that are welling up inside of the dreamer-- he or she fears being overwhelmed, or "drowning" in the feelings and being unable to think or act rationally. Again, the irony is that if the tidal wave dream is remembered in the first place, it means that the dreamer can deal with the full impact of the emotions. The first step is to acknowledge the full weight and force of these feelings.
One of the mythical or archetypal "hero/heroine's tasks" that we all must accomplish as we grow into adulthood is to face our deepest emotions without "drowning" in them. When this important task has been achieved, we are likely to dream of being surprised to discover that we are totally submerged and breathing underwater!
© Jeremy Taylor, 1996