  Using a complex representation of the Debney-Kerr-Schild (DKS) solutions and
the Kerr theorem we analyze the boosted Kerr geometries and give the exact and
explicit expressions for the metrics, the principal null congruences, the
coordinate systems and the location of the singularities for arbitrary value
and orientation of the boost with respect to the angular momentum. In the
limiting, ultrarelativistic case we obtain light-like solutions possessing
diverging and twisting principal null congruences and having, contrary to the
known pp-wave limiting solutions, a non-zero value of the total angular
momentum. The implications of the above results in various related fields are
discussed.
