There is disclosed a controlled gap seal for a gas turbine engine. The seal has a ring annularly and continuously extending about a central axis. A runner that is configured for rotation about the central axis and rotatable relative to the ring. The runner has a face facing a face of the ring. The face of the ring is spaced apart from the face of the runner by a gap. Surface discontinuities are circumferentially distributed around the central axis. The surface discontinuities are located at specific locations and distributed in specific ways. A method of using the controlled gap seal is disclosed.