Massachusetts General Laws
Chapter 90b - Motorboats, Other Vessels and Recreational Vehicles
Section 5 - Classes of Motorboats; Required Lighting, Signaling and Fire Extinguishing and Control Devices

Section 5. (a) Motorboats subject to the provisions of this chapter shall be divided into four classes as follows:—
Class A. Less than sixteen feet in length.
Class 1. Sixteen feet or over and less than twenty-six feet in length.
Class 2. Twenty-six feet or over and less than forty feet in length.
Class 3. Forty feet or over.
(b) Every motorboat in all weathers from sunset to sunrise shall carry and exhibit the following lights when underway, and during such time no other lights which may be mistaken for those prescribed shall be exhibited.
(1) Every motorboat of classes A and 1 shall carry the following lights:—
First. A bright white light aft to show all around the horizon.
Second. A combined lantern in the fore part of the vessel and lower than the white light aft, showing green to starboard and red to port, so fixed as to throw the light from right ahead to two points abaft the beam on their respective sides.
(2) Every motorboat of classes 2 and 3 shall carry the following lights:—
First. A bright white light in the fore part of the vessel as near the stem as practicable, so constructed as to show an unbroken light over an arc of the horizon of twenty points of the compass, so fixed as to throw the light ten points on each side of the vessel, namely, from right ahead to two points abaft the beam on each side.
Second. A bright white light aft to show all around the horizon and higher than the white light forward.
Third. On the starboard side a green light so constructed as to show an unbroken light over an arc of the horizon of ten points of the compass, so fixed as to throw the light from right ahead to two points abaft the beam on the starboard side. On the port side a red light so constructed as to show an unbroken light over an arc of the horizon of ten points of the compass, so fixed as to throw light from right ahead to two points abaft the beam on the port side. The said lights shall be fitted with inboard screens so set as to prevent these lights from being seen across the bow.
(3) Motorboats of classes A and 1 when propelled by sail alone shall carry the combined lantern, but not the white light aft, prescribed by subsection (b)(1) of this section. Motorboats of classes 2 and 3, when so propelled, shall carry the colored lights, suitably screened, but not the white lights prescribed by subsection (b)(2) of this section. A motorboat of classes A, 1, 2 or 3 of subsection (a) of this section when propelled by sail alone if not otherwise required or authorized by this section to carry one or more lights visible from aft, shall carry at her stern a white light, so constructed that it shall show an unbroken light over an arc of the horizon of twelve points of the compass, so fixed as to show the light six points, from right aft on each side of the vessel. Such light shall be carried as nearly as practicable on the same level as the side lights. In a small motorboat propelled by sail alone, if it is not possible on account of bad weather or other sufficient cause for this light to be fixed, an electric torch or lighted lantern shall be kept at hand ready for use, and shall, on the approach of an overtaking vessel, be shown in sufficient time to prevent collision.
(4) Every white light prescribed by this section shall be of such character as to be visible at a distance of at least two miles. Every colored light prescribed by this section shall be of such character as to be visible at a distance of at least one mile. The word ''visible'' in this subsection, when applied to lights, shall mean visible on a dark night with clear atmosphere.
(5) When propelled by sail and machinery every motorboat shall carry the lights required by this section for a motorboat propelled by machinery alone.
(c) Any vessel may carry and exhibit the lights required by the Federal Regulations for Preventing Collisions at Sea, 1948 Federal Act of October 11, 1951 (33 USC 143–147D), as amended in lieu of the lights required by subsection (b) of this section.
(d) Nothing in this section shall be construed as permitting or requiring, on waters within the marine boundary of the commonwealth which have been designated by the Commandant of the Coast Guard as international waters, the display of lights other than those required by the laws of the United States.
(e) Every motorboat of class 1, 2 or 3 shall be provided with an efficient whistle or other sound-producing mechanical appliance.
(f) Every motorboat of class 2 or 3 shall be provided with an efficient bell.
(g) Every motorboat shall carry at least one personal flotation device, as defined in section one, for each person aboard. Every motorboat of Class A, 1, 2 or 3 shall carry at least one Personal Flotation Device of Type I, II or III for each person aboard. Such devices shall be clearly labeled or imprinted as such and placed so as to be readily accessible in the motorboat and maintained in good and serviceable condition and appropriate size for whom it is intended. Devices designed to be thrown, such as a ring buoy or buoyant cushion shall be readily available on the motorboat. Devices which use kapok or fibrous glass for flotation material shall have such material encased in plastic covers. Every motorboat carrying passengers for hire shall carry at least one coast guard approved life preserver or TYPE I personal flotation device for each person on board so placed as to be readily accessible for use.
(h) Every motorboat shall be provided with such number (as specified in this subsection), size and type of fire extinguisher capable of promptly and effectually extinguishing gasoline, as may be prescribed by the regulations of the director; which fire extinguishers shall be at all times kept in condition for immediate and effective use and shall be so placed as to be readily accessible. Outboard motorboats less than twenty-six feet in length of open construction, not carrying passengers for hire, are not required to carry fire extinguishers. Fire extinguishers shall be provided as follows:—

*One B-2 hand portable fire extinguisher may be substituted for two B-1 hand portable fire extinguishers.

(i) The provisions of subsection (e), (f) and (h) shall not apply to motorboats propelled by outboard motors while competing in any race approved by the director, or while engaged in such navigation as is incidental to the tuning up of boats and engines for such race.
(j) Every motorboat shall have the carburetor or carburetors of every engine therein, except outboard motors, using gasoline as fuel, equipped with such efficient flame arrestor, backfire trap, or other similar device as may be prescribed by the regulations of the director.
(k) Every motorboat subject to the provisions of subsection (j), except open boats, using as fuel any liquid of a volatile nature, shall be provided with such means as may be prescribed by the regulations of the director for properly and efficiently ventilating the bilges of the engine and fuel tank compartments so as to remove any explosive or inflammable gases.
(l) No person shall operate or suffer or permit the operation of any motorboat which is not equipped as required by this section or modification thereof.

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