It shall be unlawful for any person to load or to operate any boat loaded with passengers or cargo in excess of its safe carrying capacity. For the purposes of this section, a violation of the following components shall constitute prima facie evidence of a violation of the provisions of this section: the maximum safe carrying capacity, in pounds, of any rowboat or any boat propelled by an outboard motor, except racing models, shall equal the product of six and one-half (6 1/2) times the total length of the boat in feet, times the greatest width of the boat in feet, times the greatest depth of the boat in feet. (§ 10, Ord. 360)