§  80.861   Required capacity.

   If the main power supply or the reserve power supply provided for the
   purpose of complying with § § 80.859 and 80.860 consists of batteries,
   the batteries must have sufficient reserve capacity available at all
   times while the vessel is leaving or attempting to leave a harbor or
   port for a voyage in the open sea, and while being navigated in the
   open sea outside of a harbor or port, to permit operation of the
   radiotelephone transmitter and the required receivers for at least 6
   hours continuously under normal working conditions.