Safe Loading — Subpart C

Category Two: Outboard Boats

Persons Capacity

Discussion:
As in all of the three boat categories, the persons capacity for outboard boats must be displayed in total pounds and whole numbers of persons. The difference in the formulae between category one and category two makes these calculations slightly more complex.

In the outboard category, from the maximum weight capacity in pounds, calculated as in section 6.1, we must deduct the weight of the engine and controls, the battery weight (dry) and the weight of a full portable fuel tank. These weights are taken from Table 4 of Subpart H of the regulation, but some explanation is needed.

Although an outboard boat may be in compliance with the Federal Regulations at the time of
construction, the same boat can be adversely affected by repowering with a heavier outboard engine. Manufacturers are encouraged to refer to the latest ABYC outboard engine weight table. Additionally, manufacturers are encouraged to review current engine weights available at the time of construction.

These capacity and flotation regulations are interrelated in different ways, and it is entirely possible that a small outboard boat, certified through calculations for a certain persons capacity, may very well fail the flotation regulation for which tests are done in the water. For this reason it may be beneficial to crosscheck the weights and calculations for both capacity and flotation.

The method to calculate the persons capacity in pounds for outboard boats (category two) is as follows:

Persons capacity (lb.) = maximum weight capacity – value in Column 6, Table 4 (U.S.C.G.),

Where:

Maximum weight capacity is as calculated in section 6.1 (33 CFR 183.35).

The value in Column 6 of Table 4 (USCG table) will be found in Appendix B. This number represents the sum of the weights of engines with controls, batteries, and full portable fuel tanks for the engine size on the U.S. Coast Guard Maximum Capacity Label. The result of this calculation is the number to display on the capacity label. If this number (persons capacity in lb.) is less than 550 pounds, it will be necessary to confirm it by conducting a dry stability test on the boat. We include this test here because many small outboard boats will fall under this requirement.

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