[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: 33CFR84.11] [Page 215] TITLE 33--NAVIGATION AND NAVIGABLE WATERS CHAPTER I--COAST GUARD, DEPARTMENT OF HOMELAND SECURITY PART 84_ANNEX I: POSITIONING AND TECHNICAL DETAILS OF LIGHTS AND SHAPES --Table of Contents Sec. 84.11 Shapes. (a) Shapes shall be black and of the following sizes: (1) A ball shall have a diameter of not less than 0.6 meter; (2) A cone shall have a base diameter of not less than 0.6 meter and a height equal to its diameter; (3) A diamond shape shall consist of two cones (as defined in paragraph (a)(2) of this section) having a common base. (b) The vertical distance between shapes shall be at least 1.5 meter. (c) In a vessel of less than 20 meters in length shapes of lesser dimensions but commensurate with the size of the vessel may be used and the distance apart may be correspondingly reduced.