There is disclosed a variety of arrangements for laying of rigid pipe from reeled storage and/or on-board welding fabrication. Thirteen independent aspects of the invention are identified. In one particular arrangement (FIGS. 3a-3b), a tilting lay tower (106) having two travelling clamps (210, 220) is provided centrally on a pipelay vessel with a radius control arch (140) pivotable to receive rigid pipe from either port or starboard lay paths. A vertical axis reel or carousel (104) is provided, within an arrangement of curved take-off arms (130, 134) and a large radius curved wall (128). By these means, pipe can be loaded onto the carousel either clockwise or anti-clockwise, and can be supplied to the lay tower via the port or starboard lay path. Continuous rigid product fabricated by a selection of welding lines (112, 114, 116) at the port side can be guided around the large radius wall either for reeling onto the carousel or for direct feeding to the lay tower. A stinger 110 at the starboard side can be used for on-loading of prefabricated pipe. A pipe elevator (150) can erect larger pipe stalks (double- or quad-joints) from deck level for welding within the tower. Flexible product can be stored within an inner compartment (1042) of the carousel and laid via the same tower. The vessel may be a reversible conversion of a FPSO.