No provision of this chapter, except Section 9-1.10 prohibiting the operation of a boat while under the influence of intoxicating liquor or narcotic drugs, shall be construed to prohibit or restrict the operation of any boat actually competing in a race or regatta over a marked course which has been previously authorized in writing and which is actively supervised by the public agency or its duly authorized agent having jurisdiction over the waters of such racing course for such purpose, nor to conflict with any of the rules adopted by the agency or its agent supervising such race, which rules govern the type, size, construction, and equipment of the boats, the navigation regulations, and other rules governing the conduct of such races. (§ 25, Ord. 360)