[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: 33CFR86.15] [Page 219] 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. 86.15 Towing vessel whistles. A power-driven vessel normally engaged in pushing ahead or towing alongside may, at all times, use a whistle whose characteristic falls within the limits prescribed by Sec. 86.03 for the longest customary composite length of the vessel and its tow.