law: Indian Ports Act, 1908
  52. Pilot to require master to hoist number 
  (1) Every pilot in charge of a vessel shall require the number
  
  of the vessel to be duly signaled as provided by the last foregoing, section.
  (2) When, on such requisition from the pilot; the master refuses
  
  to hoist the number of a vessel, or to adopt such other means of making her
  
  name known as may be practicable and usual, the pilot may, on arrival at the
  
  first place of safe anchorage, anchor the vessel and refuse to proceed on his course
  
  until the requisition has been complied with