NR 5.12(1)(a)(a) Step 1. The cubic volume of the hull shall be determined up to a reference plane (static float line) which passes through the lowest point of major leakage, such as the low point of the gunwale, transom cut-out or top of motor well, and is parallel with a line connecting the intersections of the sheer with the forward face of the stem and the sheer with the after-face of the transom. “Sheer” is defined as the intersection of the hull with deck, gunwale or super-structure. NR 5.12(1)(b)(b) Step 2. The weight capacity shall be determined by converting the hull cubic volume (Step 1) to the weight of water displaced by this volume as follows: multiply the product of Step 1 by 62.5, then subtract the weight of the vessel, and divide the remainder by a safety factor of 5. NR 5.12(1)(c)(c) Work sheet. The following work sheet (Table I) can be used in determining the weight capacity of the hull. The figures to be inserted are taken from the boat dimension drawings (Table II) to which the letters under the blank spaces refer. All dimensions should be converted to decimal numbers before insertion in the formula. Table III converts inches and eighths of inches to the decimal equivalents in feet. NR 5.12(2)(2) Determination of weight capacity of those vessels covered by s. 30.501, Stats., which have permanently installed engines, except those vessels dependent solely upon the buoyancy of pontoons or similar flotation devices. NR 5.12(2)(a)(a) Weight capacity shall be determined in the same manner as for vessels represented as being suitable for use with outboard motor except that the weight of all machinery and associated operating gear including battery, fuel and fuel system shall be subtracted. NR 5.12(3)(3) Determination of weight capacity of those vessels covered by s. 30.501, Stats., which are dependent solely upon the buoyancy of pontoons or similar flotation devices. NR 5.12(3)(a)(a) Weight capacity shall be determined by the following tests or by the substitute method provided if the conditions stated therein are met. The tests shall be conducted with the maximum horsepower motor for which the boat is recommended and with full fuel tanks and operating equipment in normal position. NR 5.12(3)(a)1.1. The transverse stability shall be tested by adding weight on the lower deck in the extreme outboard position which the arrangement permits (i.e., within one foot of the edge) until the top of the pontoon on the loaded side becomes awash. NR 5.12(3)(a)2.2. The longitudinal stability shall be tested by adding weight on the lower deck evenly about a point 1/4 of the length of the deck from forward until the edge of the lower deck becomes immersed. This test shall be repeated at the after end of the craft by adding weight evenly about a point 1/4 of the length of the deck from aft until the edge of the lower deck or the top of the motor mounting bracket becomes immersed, whichever occurs first. NR 5.12(3)(a)3.3. In a design having more than one deck intended to support passengers (i.e., having railings and means of access), the tests in subds. 1. and 2. shall also be conducted by adding weight in the specified locations on the upper deck until the conditions specified in subds. 1. and 2. respectively are attained. NR 5.12(3)(a)4.4. Ninety percent of the least of the weights attained by the tests in subds. 1. and 2. shall be the weight for passengers. TABLE I - CAPACITY FORMULA WORK SHEET
Step 1.
Compute Areas of Sections
Formula: Area = (a + 4b + 2c + 4d + e) NR 5.12 NoteNote: For maximum allowable height (H) in any section, check inside this form.
Area A = Section Quarter Length Forward:
Area B = Section Amidships:
Area C = Section Quarter Length Aft:
Area D = Section Aft:
Compute Cubic Capacity