OILFIELDS Numerous structures usually carrying navigational aids, other unlit objects and submerged obstructions sometimes marked by buoys, exist in the oilfield areas shown on this chart. In accordance with Saudi Ports Authority Notices to Mariners, the majority of such features have been omitted from this chart in oilfield areas within the Saudi Arabian EEZ. Particular care should be exercised by all vessels navigating in the vicinity of oilfields. Production platforms and associated structures, including tanker moorings, storage tankers and platforms on pipelines, generally exhibit Mo(U) lights, aircraft obstruction lights and audible fog signals. Unauthorised navigation is prohibited within 500 metres of all such structures.