law: Indian Ports Act, 1908
  4. Power to extend or withdraw the Act or certain portions
  
  thereof 
  (1) 9[***] 2[Government] may, by
  
  notification in the Official Gazette,- 
  (a) extend this Act to any port in which this
  
  Act is not in force or to any part of any navigable river or channel which
  
  leads to a port and in which this Act is not in force;
  (b) specially extend the provisions of section
  
  31 or section 32 to any port to which they have not been so extended;
  (c) withdraw this Act or section 31 or section
  
  32 from any port or any part thereof in which it is for the time being in
  
  force.
  (2) A notification under clause (a) or clause (b) of sub-section
  
  (1) shall define the limits of the area to which it refers.
  (3) Limits defined under sub-section (2) may include any piers,
  
  jetties, landing-places, wharves, quays, docks and other works made on behalf
  
  of the public for convenience of traffic, for safety of vessels or for the
  
  improvement, maintenance or good government of the port and its approaches
  
  whether within or without high-water-mark, and, subject to any rights of
  
  private property therein, any portion of the shore or bank within fifty yards
  
  of high-water-mark.
  (4) In sub-section (3) the expression
  
  "high-water-mark" means the highest point reached by ordinary spring
  
  tides at any season of the year.