[Code of Federal Regulations] [Title 33, Volume 1] [Revised as of July 1, 2005] From the U.S. Government Printing Office via GPO Access [CITE: 33CFR86.03] [Page 218] TITLE 33--NAVIGATION AND NAVIGABLE WATERS CHAPTER I--COAST GUARD, DEPARTMENT OF HOMELAND SECURITY PART 86_ANNEX III: TECHNICAL DETAILS OF SOUND SIGNAL APPLIANCES--Table of Contents Subpart A_Whistles Sec. 86.03 Limits of fundamental frequencies. To ensure a wide variety of whistle characteristics, the fundamental frequency of a whistle shall be between the following limits: (a) 70-200 Hz, for a vessel 200 meters or more in length; (b) 130-350 Hz, for a vessel 75 meters but less than 200 meters in length; (c) 250-525 Hz, for a vessel less than 75 meters in length.