. . . . "and elsewhere" . "German U-Boats" . "German submarines" . "''Unterseeboot''" . . "with submarines" . "Submarines" . "German submarine" . . . "torpedo attacks" . "U-boot" . "Enemy submarines" . . . . . "U-Boot-Waffe" . . . . . . . . . . . . "torpedoed" . "Type VII U-boat" . . . . . "German counterparts" . . . . "covertly develop her U-boat fleet" . "U-boats' torpedo attacks" . "designs" . . "German U-boats in World War I" . "Nazi German submarine" . "German U-boats" . . "U-18" . . "submarine menace" . . "submarine" . . . . . "U-Boot" . . . . . "U-Boats" . . . . "Submarine" . . . . . "U-boat" . . . . . "submarines" . . "Unterseeboot" . "German submarine warfare" . . "U-boats" . "U-Boat" . . "German U-boat" . . . "U-51" . . . . . "U-boat" . . . "u-boat" . . . . . "U Boat" . . "Lists of U" . . "U-boats." . . . "German submarine raiders" . .