Sec.  80.106   Intercommunication in the mobile service.

   (a) Each public coast station must exchange radio communications with any
   ship or aircraft station at sea; and each station on shipboard or aircraft
   at sea must exchange radio communications with any other station on
   shipboard or aircraft at sea or with any public coast station.

   (b) Each public coast station must acknowledge and receive all
   communications from mobile stations directed to it, transmit all
   communications delivered to it which are directed to mobile stations within
   range in accordance with their tariffs. Discrimination in service is
   prohibited.