The marine pipelaying system for vertical or near vertical laying of an offshore pipeline includes a main supporting structure; a pipe connecting station, wherein a pipe section is connected to an uppermost end of a previously launched pipeline; a static clamp adapted for releasably securing the uppermost end of the previously launched pipeline, wherein the static clamp is adapted to support the weight of the previously launched pipeline; a mobile clamp adapted for releasably securing the previously launched pipeline at a position below the static clamp, wherein the mobile clamp is adapted to support the weight of the offshore pipeline as the offshore pipeline is released from the static clamp; and a mobile clamp hoist connected to the mobile clamp.