If a boater has a VHF radio, it is best to call MCTS (Coast Guard radio) on VHF Channel 16 to make a mayday or pan pan call, as required. If they do not have a VHF radio, then they should contact Coast Guard radio via cell phone *16. Contacting JRCC using *727 or calling 911 should only be used as last resort alternatives.
If you are on land and need to report a boater who is overdue according to their sail plan and you have not been able to establish contact with them, or want to report a suspicious looking vessel (ex. overturned), contact Coast Guard radio via cell phone *16 or the Joint Rescue Coordination Center