[Code of Federal Regulations]
[Title 33, Volume 2]
[Revised as of July 1, 2001]
From the U.S. Government Printing Office via GPO Access
[CITE: 33CFR183.53]

[Page 763-765]
 
                TITLE 33--NAVIGATION AND NAVIGABLE WATERS
 
    CHAPTER I--COAST GUARD, DEPARTMENT OF TRANSPORTATION (CONTINUED)
 
PART 183--BOATS AND ASSOCIATED EQUIPMENT--Table of Contents
 
                        Subpart D--Safe Powering
 
Sec. 183.53  Horsepower capacity.

    The maximum horsepower capacity marked on a boat must not exceed the 
horsepower capacity determined by the computation method discussed in 
paragraph (a) of this section, or for certain qualifying boats, the 
performance test method discussed in paragraph (b) of this section.
    (a) The maximum horsepower capacity must be computed as follows:
    (1) Compute a factor by multiplying the boat length in feet by the 
maximum transom width in feet excluding handles and other similar 
fittings, attachments, and extensions. If the boat does not have a full 
transom, the transom width is the broadest beam in the aftermost quarter 
length of the boat.
    (2) Locate horsepower capacity corresponding to the factor in Table 
183.53.
    (3) For a boat with a factor over 52.5, if the horsepower capacity 
calculated in Table 183.53 is not an exact multiple of 5, it may be 
raised to the next exact multiple of 5.
    (4) For flat bottom hard chine boats with a factor of 52 or less, 
the horsepower capacity must be reduced by one horsepower capacity 
increment in Table 183.53.

                                 Table 183.53--Outboard Boat Horsepower Capacity
                                  [Compute: Factor=Boat Length X Transom Width]
If factor (nearest integer) is......................        0-35       36-39       40-42       43-45       46-52
----------------------------------------------------------------------------------------------------------------
Horsepower Capacity is..............................           3           5         7.5          10          15
----------------------------------------------------------------------------------------------------------------

[Note: For flat bottom hard chine boats, with factor of 52 or less, reduce one capacity limit (e.g. 5 to 3)]


----------------------------------------------------------------------------------------------------------------
                                                                  No remote steering, or less than 20" transom
                                        Remote steering and at                       height
 If factor is over 52.5 and the boat      least 20" transom    -------------------------------------------------
                 has                            height            For flat bottom hard
                                                                      chine boats            For other boats
----------------------------------------------------------------------------------------------------------------
Horsepower capacity is (raise to       (2 X Factor) -90.......  (0.5 X Factor) -15.....  (0.8 X Factor) -25
 nearest multiple of 5).
----------------------------------------------------------------------------------------------------------------


[[Page 764]]

    (b) For boats qualifying under this paragraph, the performance test 
method described in this paragraph may be used to determine the 
horsepower capacity.
    (1) Qualifying criteria.

    (i) Thirteen feet or less in length;
    (ii) Remote wheel steering;
    (iii) Transom height
    (A) Minimum 19 inch transom height; or,
    (B) For boats with at least a 19 inch motorwell height, a minimum 15 
inch transom height;

    (iv) Maximum persons capacity not over two persons;
    (2) Boat preparation.
    (i) The boat must be rigged with equipment recommended or provided 
by the boat and motor manufacturer and tested with the highest 
horsepower production powerplant for which the boat is to be rated, not 
to exceed 40 horsepower.
    (ii) Standard equipment must be installed in accordance with 
manufacturers' instructions.
    (iii) The lowest ratio (quickest) steering system offered on the 
boat model being tested must be installed.
    (iv) The outboard motor must be fitted with the manufacturer's 
recommended propeller providing maximum speed.
    (v) Standard permanently installed fuel tanks must be no more than 
one-half full. Boats without permanent tanks must be tested with one 
full portable tank.
    (vi) Portable tanks must be in their designated location or placed 
as far aft as possible.
    (vii) The outboard motor must be placed in the lowest vertical 
position on the transom or, if mounting instructions are provided with 
the boat, at the height recommended.
    (viii) Boat bottom, motor and propeller must be in new or almost new 
condition.

    Note: The use of the following special equipment should be 
considered because of the potential for exceeding the capabilities of 
the boat while performing the test:
Racing Type Personal Flotation Device
Helmet.

    (3) Test conditions. Testing must be conducted on smooth, calm water 
with the wind speed below 10 knots. The test must be conducted with no 
load other than a driver who must weigh no more than 200 pounds. The 
motor trim angle must be adjusted to provide maximum full throttle speed 
short of excessive porpoising or propeller ventilation or 
``cavitation'', so that there is no loss of directional control.
    (4) Quick turn test procedure. Set throttle at a low maneuvering 
speed and steer the boat straight ahead. Turn the steering wheel 
180 deg. in the direction of least resistance in \1/2\ second or less 
and hold it at that position without changing the throttle or trim 
settings during or after the wheel change. The boat completes the 
maneuver successfully if it is capable of completing a 90 deg. turn 
without the driver losing control of the boat or reducing the throttle 
setting. Gradually increase the boat's turn entry speed incrementally 
until the boat does not complete the Quick Turn Test successfully or 
successfully completes it at maximum throttle.

    Note: It is recognized that operator skill and familiarity with a 
particular boat and motor combination will affect the test results. It 
is permissible to make a number of practice runs through the quick turn 
test at any throttle setting.

    (5) Test course method. Set throttle for 30 miles per hour boat 
speed and run the test course set up in accordance with Figure 183.53, 
passing outside the designated avoidance marker for 35 to 37.5 miles per 
hour without contacting any of the course markers. If the boat 
successfully completes this run of the test course, increase the 
throttle setting to 35 to 37.5 miles per hour boat speed and run the 
course passing outside the designated avoidance marker for that speed 
without contacting any of the course markers. If the boat successfully 
completes this run of the test course and the motor was not at full 
throttle, increase the throttle setting to 37.5 to 42.5 miles per hour 
boat speed and run the course passing outside the designated avoidance 
marker for that speed without contacting any of the course markers. If 
the boat successfully completes this run of the test course and the 
motor was not at full throttle, increase the throttle setting to 42.5 
miles per hour or more and run the course passing outside the designated 
avoidance marker for that

[[Page 765]]

speed without contacting any of the course markers. If the boat 
successfully completes this run of the test course and the motor was not 
at full throttle, continue to increase the throttle setting and run the 
test course passing outside the designated avoidance marker for 42.5 
miles per hour or more until the boat fails to complete the test 
successfully or the boat completes the test course maneuvers 
successfully at full throttle. The boat successfully completes the test 
course if the driver is able to maneuver it between the designated 
avoidance markers without striking the markers and without losing 
control of the boat or reducing the throttle setting. There must be no 
change in position of any equipment on board and there must be no change 
of position of personnel in order to influence the test results. There 
must be no instability evidenced by oscillating motion in the roll or 
yaw axes exhibited while negotiating the course.

    Note: It is recognized that operator skill and familiarity with a 
particular boat and motor combination will affect the test results. It 
is therefore considered permissible to make a number of practice runs 
through the test course at any throttle setting.

    (6) Maximum horsepower capacity. (i) For boats capable of less than 
35 miles per hour, the maximum horsepower capacity must be the maximum 
horsepower with which the boat was able to successfully complete the 
Quick Turn Test Procedure in Sec. 183.53(b)(4) at full throttle or the 
maximum horsepower determined under the calculations in Sec. 183.53(a) 
of this section.
    (ii) For boats capable of 35 miles per hour or more, the maximum 
horsepower capacity must be the maximum horsepower with which the boat 
was able to successfully complete both the Quick Turn Test Procedure in 
Sec. 183.53(b)(4) and the Test Course Method in Sec. 183.53(b)(5) at 
full throttle or the calculations in Sec. 183.53(a) of this section.
    (iii) The maximum horsepower capacity determined in accordance with 
Sec. 183.53(b) must not exceed 40 horsepower.

  Figure 183.53.--Boat Horsepower Capacity Test Course--35 mph or more
[GRAPHIC] [TIFF OMITTED] TC18OC91.021

[CGD 85-002, 51 FR 37574, Oct. 23, 1986]

Subpart E  [Reserved]