A rigid-to-flexible connector (RFC) is provided on the rigid pipe section instead of a pipeline end termination (PLET), and the pipe end having the RFC is raised to the surface of the sea, while leaving a portion of the rigid pipe section on the seabed. The RFC is then connected to one end of the flexible pipe section, and the latter lowered to the seabed, with the raised, end of the rigid pipe section attached, to return the rigid pipe section to the seabed. Since the RFC on the rigid pipe section is connected to the flexible pipe section at the surface of the sea, the RFC can have a simpler, lighter, technical design, resulting in significant cost, manufacturing time and quality control time savings.