Mass. Gen. Laws ch. 130 § 38A
No person or persons shall take or attempt to take, by diving, lobsters, or edible crabs from the coastal waters, unless he displays his lobster license number upon his air tank, and for each person diving alone or for each group of divers upon the surface of said waters, in the area where the person or persons is taking or attempting to take lobsters and edible crabs, a floating marker shall be displayed with the license number of each person diving alone or in the case of any group of divers the license number of every person taking or attempting to take lobsters shall be displayed. Said number on a floating marker shall be displayed in the form of a single panel not less than twelve inches in height and width and shall be buoyed in an upright position. The marker shall have a white background with the licensee's number, or in the case of a group the licensees' numbers, displayed on both sides thereof by black numerals of a size prescribed by regulation of the director.
No person shall take or attempt to take with the aid and use of a boat any lobsters or edible crabs by pots, traps or other contrivances designed or adapted to the taking of lobsters or edible crabs without first displaying the buoy colors used by him in accordance with his license by painting the color or colors (a) on each side of the hull or upon panels attached to each side of the hull, or (b) upon both sides of a single panel which is attached to the boat on top of the bow, or by mounting a buoy, not less than eleven inches in length, and four inches in diameter, with his color scheme thereon, in an upright position at least six inches above the roof of the boat. Color schemes painted on the hull of the boat or upon panels shall be displayed as a solid colored strip four inches high and eighteen inches long, each strip abutting another on the longest side, if more than one color, to form a rectangle or square. The rectangle or square thus formed shall have a black border all the way around at least one inch wide. All color schemes so displayed shall be clearly visible from both sides of the boat.
Mass. Gen. Laws ch. 130, § 38A