[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: 33CFR174.27] [Page 886] TITLE 33--NAVIGATION AND NAVIGABLE WATERS CHAPTER I--COAST GUARD, DEPARTMENT OF HOMELAND SECURITY(CONTINUED) PART 174_STATE NUMBERING AND CASUALTYREPORTING SYSTEMS--Table of Contents Subpart B_Numbering System Requirements Sec. 174.27 Duration of certificate of number. A certificate of number must not be valid for more than 3 years.