Section 5(2) in The Madras Port Petroleum Rules, 1963
(2)No vessel shall enter the enclosed harbour from the Petrol Berth after having discharged dangerous petroleum, until the tanks which contained dangerous petroleum have been gas-freed and a a certificate has been obtained by the Master from an officer appointed in this behalf by Government, to the effect that such officer has, after examination with the aid of vapour testing instrument, found the vessel to be entirely clear of dangerous petroleum and petroleum vapour.Such certificates shall be exhibited at the gangway of the vessel.
