law: The Inland Vessels Act, 2021
  Chapter II
  Declaration of Inland water area into zones
  4. Declaration of inland water area into Zones.-
  (1) The State Government may, for the purposes of this Act, declare by notification any inland water area to be a "Zone" depending on the maximum significant wave height criteria specified in sub-section (2).
  (2) For the purposes of sub-section (1), the State Government may classify the maximum significant wave height criteria into the following Zones, namely:-
  (i) Zone 1 refers to the area (other than Zone 2 or Zone 3) where the maximum significant wave height does not exceed 2.0 metres;
  (ii) Zone 2 refers to the area (other than Zone 3) where the maximum significant wave height does not exceed 1.2 metres; and
  (iii) Zone 3 refers to the area where the maximum significant wave height does not exceed 0.6 metres.