[Code of Federal Regulations] [Title 33, Volume 2] [Revised as of July 1, 2008] From the U.S. Government Printing Office via GPO Access [CITE: 33CFR173.15] [Page 878] TITLE 33--NAVIGATION AND NAVIGABLE WATERS CHAPTER I--COAST GUARD, DEPARTMENT OF HOMELAND SECURITY(CONTINUED) PART 173_VESSEL NUMBERING AND CASUALTY ANDACCIDENT REPORTING--Table of Contents Subpart B_Numbering Sec. 173.15 Vessel number required. (a) Except as provided in Sec. 173.17, no person may usea vessel to which this part applies unless: (1) It has a number issued on a certificate of number by theissuing authority in the State in which the vessel is principallyused; and (2) The number is displayed as described in Sec. 173.27. (b) This section does not apply to a vessel for which a validtemporary certificate has been issued to its owner by the issuingauthority in the State in which the vessel is principally used.