[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: 33CFR67.10-1] [Page 167] TITLE 33--NAVIGATION AND NAVIGABLE WATERS CHAPTER I--COAST GUARD, DEPARTMENT OF HOMELAND SECURITY PART 67_AIDS TO NAVIGATION ON ARTIFICIAL ISLANDS AND FIXED STRUCTURES --Table of Contents Subpart 67.10_General Requirements for Sound signals Sec. 67.10-1 Apparatus requirements. Source: CGD 72-74R, 37 FR 13512, July 8, 1972, unless otherwise noted. The sound signal required by Sec. Sec. 67.20-10, 67.25-10, and 67.30-10 must: (a) Have its maximum intensity at a frequency between 100 and 1,100 Hertz; (b) Sound a 2-second blast every 20 seconds (2 seconds sound, 18 seconds silence) unless otherwise authorized by the District Commander; (c) Have the rated range required by Sec. 67.20-10, Sec. 67.25-10, or Sec. 67.30-10; (d) Have a height not exceeding 25 feet; (e) Have not more than eight sound sources; (f) Be approved by the Coast Guard under Sec. 67.10-15; and (g) Be permanently marked with: (1) The date of Coast Guard approval; (2) The manufacturer and date of manufacture; (3) A model designation; (4) The approved range; and (5) The power necessary to comply with the provisions of paragraph (c) of this section.