A certificate of number is granted for a number issued under this chapter. The certificate shall be at all times available for inspection on the vessel for which issued when the vessel is in operation, and may be in hard copy or digital form. Any certificate issued in hard copy under this section shall be pocketsized. The certificate shall be valid for not more than 3 years. 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. A vessel that does not have the certificate of number on board shall be identified when in operation, and comply with requirements, as the issuing authority prescribes.