Abstract: A sonar/television system and method is disclosed whereby an underwater drill pipe may be guided to a re-entry guide base or assembly positioned on a sea floor. The system includes a scanner assembly having first and second elongated housings whose exterior dimensions enable insertion of the housings into the bore of the drill pipe. The upper end of the first housing is rotatably mounted to the lower end of the second housing. A television camera is disposed within the first housing and fixed to the second housing so that the camera remains fixed when the first housing is rotated, and a sonar transducer is mounted in the first housing to rotate therewith. Scenes viewed by the camera are reproduced on a screen of a television display apparatus in such a manner that, when the re-entry guide base is within view, markings on the screen indicate both the lateral positioning of the drill pipe relative to the guide base and also the altitude of the drill pipe above the guide base.