[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: 33CFR86.01] [Page 217-218] 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. 86.01 Frequencies and range of audibility. Subpart A_Whistles Sec. 86.01 Frequencies and range of audibility. 86.03 Limits of fundamental frequencies. 86.05 Sound signal intensity and range of audibility. 86.07 Directional properties. 86.09 Positioning of whistles. 86.11 Fitting of more than one whistle. 86.13 Combined whistle systems. 86.15 Towing vessel whistles. Subpart B_Bell or Gong 86.21 Intensity of signal. 86.23 Construction. Subpart C_Approval 86.31 Approval. [Reserved] Authority: Sec. 3, Pub. L. 96-591; 49 CFR 1.46(n)(14). Source: CGD 81-009, 46 FR 61848, Dec. 21, 1981, unless otherwise noted. [[Page 218]] The fundamental frequency of the signal shall lie within the range 70-525 Hz. The range of audibility of the signal from a whistle shall be determined by those frequencies, which may include the fundamental and/ or one or more higher frequencies, which lie within the frequency ranges and provide the sound pressure levels specified in Sec. 86.05.