Code of Federal Regulations Title 33. Navigation and Navigable Waters § 33.173.21 Certificate of number required

(a) Except as provided in §§ 173.13 and 173.17, no person may operate a vessel to which this part applies unless it has on board:

(b)Section 12304(a) of Title 46, United States Code, states in part:  The certificate of number for a vessel less than 26 feet in length and leased or rented to another for the latter's noncommercial operation of less than 7 days may be retained on shore by the vessel's owner or representative at the place from which the vessel departs or returns to the possession of the owner or the owner's representative.