law: 18. Exemption from payment of light-dues.
  The following ships shall be exempted from the payment of light-dues under this Act, namely:
  (a) any ship belonging to Government 3*** or to a foreign Prince or State and not carrying cargo or passenger for freight or fares ; and
  (b) any ship of a tonnage of less than fifty tons ;
  and the Central Government may, by notification in the Official Gazette, exempt any other ships, or classes of ships or ships performing specified voyages from such payment either wholly or to such extent only as may be specified in the notification.