Abstract: A pipe lay vessel with a reel for carrying a length of pipe and first drive part for controlling rotation of the reel. A substantially vertical guide structure includes at its upper end a deflection member for deflecting the pipe from a first trajectory extending between the reel and the guide structure to a second, substantially vertical trajectory. A clamping member carries the vertical pipe section and has second drive for feeding the pipe along the vertical trajectory. A movable tension compensator (7) is provided at the first pipe trajectory for lengthening or shortening the first pipe trajectory to maintain a substantially constant tension of the pipe along the first trajectory during unwinding of the reel.