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Hope this answers your questions, the data is from the USCG boatbuilders handbook:

FEDERAL LAW Subpart B - Display of Capacity Information

33 CFR SECTIONS 183.21-183.27
Revised as of July 1, 2000
183.21 - Applicability

This subpart applies to monohull boats less than 20 feet in length, except sailboats, canoes, kayaks, and inflatable boats.

Each boat must be marked in the manner prescribed in Sec.s 183.25 and 183.27 with the maximum persons capacity in whole numbers of persons and in pounds, the maximum weight capacity in pounds, determined under Sec.s 183.33 through 183.43, and the maximum horsepower capacity determined under Sec. 183.53 or the statement “This Boat Not Rated for Propulsion by a Motor”.

(a) Each marking required by Sec. 183.23 must be permanently displayed in a legible manner where it is clearly visible to the operator when getting the boat underway.

(b) The information required by Sec. 183.23 must be displayed in the following manner:

(1) For outboard boats:

U.S. Coast Guard Maximum Capacities
XX Persons or XXX Pounds
XXX Pounds, persons, motor, gear
XXX Horsepower, motor
or
U.S. Coast Guard Maximum Capacities
XX Persons or XXX Pounds
XXX Pounds, persons, motor, gear
XXX Horsepower, motor with remote steering
XXX Horsepower, motor without remote steering

(2) For inboard boats and inboard-outboard boats:

U.S. Coast Guard Maximum Capacities
XX Persons or XXX Pounds
XXX Pounds, persons, gear

(3) For boats rated for motors of 2 horsepower or less:

U.S. Coast Guard Maximum Capacities
XX Persons or XXX Pounds
XXX Pounds, persons, motor, gear
XXX Horsepower, motor

(4) For boats rated for manual propulsion:

U.S. Coast Guard Maximum Capacities
XX Persons or XXX Pounds
XXX Pounds, persons, gear
This boat not rated for propulsion by motor

(c) The capacity information displays required in paragraph (b) must meet the following.

(1) The capacity information required in Sec. 183.23 must be displayed within a yellow area that -

(i) Is at least 4 inches wide; and
(ii) Is high enough that each line of print is separated by at least 1/8 inch from each other and from the borders of the yellow area;

(2) The persons capacity in whole numbers must be black print with the following dimensions:

(i) The height must not be smaller than one-half inch;
(ii) The width of the numbers must be three-fifths of the height except for the number “4”, which shall be one stroke width wider, and the number “1” which shall be one stroke in width;
(iii) The stroke width shall be one-sixth of the height; and
(iv) The minimum space between the numbers shall be one stroke width.

(3) The words in the line “XX Persons or XXX Pounds” must be at least one-quarter inch in height but not larger than one-half the height of the persons capacity number and of a color contrasting with yellow. The number of pounds in this line must be at least one- eighth inch in height but no larger than one-half the height of the persons capacity number and of a color contrasting with yellow.

(4) All remaining words and numbers required to be within the yellow area required in paragraph (c) (1) must be at least one-eighth inch in height, but no larger than one-half the height of the persons capacity number.

(5) All other words and numbers on the displays must be located outside the yellow area on a background color which contrasts with yellow.

(6) The words “Maximum Capacities” must be at least one-quarter inch in height and of color contrasting with its background.

(7) The words “U. S. Coast Guard” must be at least one-eighth inch in height and of color contrasting with its background.

Each marking required by Sec. 183.23 must be:

(a) Capable of withstanding the combined effects of exposure to water, oil, salt spray, direct sunlight, heat, cold, and wear expected in normal operation of the boat, without loss of legibility; and

(b) Resistant to efforts to remove or alter the information without leaving some obvious sign of such efforts.

Discussion:
The requirements in this subpart are simple and straightforward. The important section is 183.25 (b), which gives the arrangement options for the figures. The regulation follows the categories explained before, but breaks down category three so as to be more explicit. Following are some comments on this.

An outboard boat has two optional display forms: a regular outboard with a helm seat or steering station will simply display the information as shown in 183.25 (b) (1), but, if the vessel is a small boat on which the final owner may have the option of installing either a tiller-steered engine or a remote steering system, the regulation offers an option to certify a horsepower capacity for the tiller-steered engine, and a different horsepower capacity for a remotely steered engine.

The labels on inboard or sterndrive boats do not display a certification of the maximum horsepower capacity because the engine is already installed at the factory. Therefore, the display will only show the persons capacity in pounds and whole numbers and the maximum weight capacity. Remember that technically, the persons capacity in pounds can be the same as the maximum weight capacity.

Finally, category three is broken down into two groups: boats rated for 2 HP or less in which the manufacturer certifies identically to the regular outboard boats above; and boats rated for manual propulsion in which no horsepower capacity is given and a note is added at the bottom of the label stating, “This Boat Not Rated for Propulsion by Motor.”

Part 183.27 deals with the requirements for the construction of the label, including the fact that the label must withstand environmental effects without loss of legibility. In reality, the manufacturer will probably procure these labels from a supplier that already complies with these requirements. It is not practical for boat manufacturers to make their own labels.