[Code of Federal Regulations] [Title 33, Volume 2] [Revised as of July 1, 2003] From the U.S. Government Printing Office via GPO Access [CITE: 33CFR150.311] [Page 223] TITLE 33--NAVIGATION AND NAVIGABLE WATERS CHAPTER I--COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PART 150--OPERATIONS--Table of Contents Subpart C--Vessel Navigation Sec. 150.311 Radio listening watch. Whenever a tanker is in the safety zone, the Vessel Traffic Supervisor and the master of the tanker shall each continuously monitor the radio frequency designated in the Operation Manuals for use by tankers and support vessels underway at the port, except when transmitting on that frequency.