Physically accounting for all deck penetrations allowing for preparation and implementation of zero discharging of any liquid discharging overboard using Ship Yard As Built (SYAB) alone, is fraught with problems and uncertainties. Firstly, the As Installed information of deck drains, scuppers and opening rarely find its way back to the previously Approved For Construction Drawings (AFC) and secondly, adding or relocating or blanking off deck drains / penetrations are routinely done to assure deck is kept dry. As such, to meet MARPOL’s requirements, Rig Engineering has accounted for all deck opening using 3D colour laser scanning technology. With the captured cloud scan, spool piece, tie ins, pipe supports and candidate hangers for scaffolding during installation can be pre planned, well ahead of the vessel arriving for the actual installation. In this real life case study, a series of colour laser scan were done from under deck on the pontoon to identify all the openings that are detectable and forms part of the manifolding system to collecting tank on one of the stability columns of the vessel. This can then be discharged at suitable interval as required, to supply vessel and offload to shore side.