Section 1. In this chapter, unless the context otherwise requires, the following words shall have the following meanings:

''Amphibious landing vehicle'',—a motor vehicle that can travel on land and water.

''Boating accident'',—an occurrence in which a waterborne vessel subject to this chapter is involved, whether or not there has been any actual collision, and which results in damage by or to such vessel or its equipment, or by or to an object or person being towed, pushed or propelled by such vessel, or in which there is an injury to any person, loss of life, or disappearance of any person under circumstances which indicate the possibility of death or injury or disappearance of a vessel other than by theft.

''Certificate of Number'',—a document issued by the director, upon application therefor, stating the name and address of the owner of, and the number awarded to a vessel subject to this chapter, except such vessels, other than livery boats, owned by a manufacturer of or dealer in boats.

''Commissioner'',—the commissioner of the department of fisheries, wildlife and environmental law enforcement.

''Department'',—the department of fisheries, wildlife and environmental law enforcement of the executive office of environmental affairs.

''Director'',—the director of the division of law enforcement of the department of fisheries, wildlife and environmental law enforcement.

''Division'',—the division of law enforcement of the department of fisheries, wildlife and environmental law enforcement.

''Horsepower'',—the aggregate rated horsepower of all propellant machinery at maximum operating revolutions per minute.

''Identification number'', —the number awarded to a vessel subject to this chapter and upon approval of an application for a certificate of number.

''Jet skis'',—a ski propelled by machinery and designed to travel over water.

''Length'',—the extreme deck fore-and-aft measurement of a vessel.

''Like offense'', —as used in subsection (a) of section eight, shall mean any violation of paragraph (1) of subsection (a) of section eight, or any violation of subparagraph (1) of paragraph (a) of subsection (1) of section twenty-four of chapter ninety.

''Livery boat'',—a boat hired or available for hire from a person who offers boats for hire as a regular business.

''Machinery'',—all inboard and outboard engines and all other types of motors or mechanical devices capable of propelling vessels.

''Motorboat'',—any vessel propelled by machinery whether or not such machinery is the principal source of propulsion, but not 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.

''Operate'',—navigate or otherwise use a motorboat or vessel.

''Operator'',—a person who operates or who has a charge of the navigation or use of a motorboat or vessel.

''Owner'',—the person who claims lawful possession of a vessel by virtue of legal title or equitable interest therein which entitles him to possession.

''Person'', a natural person, corporation, association, partnership or other legal entity or other legal agency or political subdivision.

''Personal flotation devices'',—TYPE I, a coast guard approved device designed to turn an unconscious person in the water from a face downward position to a vertical or slightly backward position, and to have more than twenty pounds of buoyancy. Acceptable for all size boats. TYPE II, a coast guard approved device designed to turn an unconscious person in the water from a face downward position to a vertical or slightly backward position and to have at least fifteen and five-tenths pounds of buoyancy. Acceptable for all size boats. TYPE III, a coast guard approved device designed to keep a conscious person in a vertical or slightly backward position and to have at least fifteen and five-tenths pounds of buoyancy. While having the same buoyancy as TYPE II, the TYPE III has a lesser turning ability to allow for a comfortable design for water activities such as water skiing. Acceptable for all size boats. TYPE IV, a coast guard approved device designed to be thrown to a person in the water and not worn. It is designed to have at least sixteen and five-tenths pounds of buoyancy. Acceptable for all boats as a throwable device only.

''Registrar'', —the registrar of motor vehicles.

''Secretary'',—the Secretary of the Department of the United States government in which the coast guard is operating.

''Ship's lifeboats'',—boats carried aboard a vessel and used solely for lifesaving purposes, but not including dinghies, tenders, speedboats or other types of craft carried aboard a vessel and used for other than lifesaving purposes.

''Surf jet'',—a surfboard propelled by machinery and designed to travel over water.

''Underway'',—not an anchor, made fast to the shore or aground.

''Vessel'',—watercraft of every description, except a seaplane on the water used or capable of being used as a means of transportation on water.

''Waters of the commonwealth'',—all coastal and inland waters as defined in section one of chapter one hundred and thirty-one except ponds less than ten acres in area and owned by one person, and is not open to the public.

''Wetbike'',—a vessel designed to travel over water, supported by skis propelled by machinery.