A guide system configured to guide a pipeline from a laying vessel onto the bed of a body of water has a float unit; a trolley, which is housed inside the frame, is selectively connectable to a pipeline spanning a given or designated path between the laying vessel and the bed of the body of water, and is configured to roll along the pipeline, parallel to the given or designated path; and at least one motor connected to the trolley) to selectively adjust the distance between the float unit and the laying vessel.