Abstract: .Iadd.A method of laying pipe on the floor of a body of water to form a pipeline in which the pipe section to be joined is at all times securely and stably supported by a mobile frame such that, during alignment and engagement, the pipe is substantially free from the influence of wave and current action. A pipe section is first releasably attached to a mobile frame, then lowered to the floor where it is placed in a stable-fixed position on the floor generally aligned with but spaced from the end of the previously laid pipe. The end is then aligned with the pipeline by lateral and/or tilting movement of the frame, and then moved axially into engagement with the end of the pipeline. The alignment and engagement procedures may be observed, directed and/or controlled from a region at atmospheric pressure. The method may also include holding the engaged pipe section in a stable position while placing ballast material thereunder. After engagement, the frame is released from the section and returned to the surface..