Missouri Revised Statutes Title XIX. Motor Vehicles, Watercraft and Aviation § 306.126. Motorboats, regulations as to passenger seating while under way--person in water, flag required, when--slow speed required, when--penalty

1. The operator of a motorboat shall not allow any person to ride or sit on the gunwales, decking over the bow, railing, top of seat back or decking over the back of the motorboat while under way, unless such person is inboard of adequate guards or railing provided on the motorboat to prevent a passenger from being lost overboard. As used in this section, the term “adequate guards or railing” means guards or railings having a height parameter of at least six inches but not more than eighteen inches. Nothing in this section shall be construed to mean that passengers or other persons aboard a motorboat cannot occupy the decking over the bow of the boat to moor it to a mooring buoy or to cast off from such a buoy, or for any other necessary purpose. The provisions of this section shall not apply to vessels propelled by sail or vessels propelled by jet motors or propellers operating on a stretch of waterway not created or widened by impoundment.

2. Whenever any person leaves any watercraft, other than a personal watercraft, on the waters of the Mississippi River, the waters of the Missouri River or the lakes of this state and enters the water between the hours of 11:00 a.m. and sunset, the operator of such watercraft shall display on the watercraft a red or orange flag measuring not less than twelve inches by twelve inches. The provisions of this subsection shall not apply to watercraft that is moored or anchored. The flag required by this subsection shall be visible for three hundred sixty degrees around the horizon when displayed and shall be displayed only when an occupant of the watercraft has left the confines of the watercraft and entered the water. The flag required by this subsection shall not be displayed when the watercraft is engaged in towing any person, but shall be displayed when such person has ceased being towed and has reentered the water.

3. No operator shall knowingly operate any watercraft within fifty yards of a flag required by subsection 2 of this section at a speed in excess of a slow-no wake speed.