(1) "Vessel" means every description of watercraft, other than a seaplane on the water, used or capable of being used as a means of transportation on water;
(2) "Motorboat" means any vessel propelled by an electrical, steam, gas, diesel or other fuel propelled or driven motor, whether or not the motor is the principal source of propulsion, but does not include a vessel which has a valid marine document issued by the bureau of customs of the United States government or any federal agency successor thereto;
(3) "Owner" means a person, other than a lienholder, having the property in or title to a motorboat. The term includes a person entitled to the use or possession of a motorboat subject to an interest in another person, reserved or created by agreement and securing payment or performance of an obligation, but the term excludes a lessee under a lease not intended as security;
(4) "Commissioner" means the commissioner of the division of motor vehicles;
(5) "Director" means the director of the division of natural resources; and
(6) "Personal watercraft" means a small vessel of less than sixteen feet in length which uses an inboard motor powering a water jet pump as its primary source of motive power and which is designed to be operated by a person sitting, standing, or kneeling on the vessel, rather than the conventional manner of sitting or standing inside the vessel. For purposes of this article, the term "personal watercraft" also includes "specialty prop-crafts" which are vessels similar in appearance and operation to a personal watercraft but which are powered by an outboard motor or propeller driven motor.