Except for the uplift of sea stores (i.e. goods supplied for consumption or use on board a vessel by the crew and passengers outside Singapore waters) to vessels berthed at authorised shipyards, shipyards are not authorised for the importation, exportation and transhipment of all other cargo. You are required to import all other such cargo via one of the authorised piers or places, e.g. Free Trade Zone, instead. Notwithstanding this, certain cargo may be allowed to be imported or exported via private waterfront locations on a one-time basis, subject to Customs' approval, provided that certain criteria are met. For more details on such importation of cargo on a one-time basis, please see here.