Section 181.23 - Hull identification numbers required(a) A manufacturer must identify each boat produced or imported with primary and secondary hull identification numbers permanently affixed in accordance with § 181.29 of this subpart.(b) A person who manufactures or imports a boat for his or her own use and not for sale must obtain the required hull identification number in accordance with the requirements of the issuing authority listed in 33 CFR part 173, Appendix A for the boat's State of principal operation and permanently affix the HIN to the boat in accordance with § 181.29 of this subpart.(c) No person may assign the same HIN to more than one boat.USCG-2003-14963, 77 FR 18703 , Mar. 28, 2012