Section 9A. No person shall operate a jet ski, surf jet or wetbike (a) on waters of the commonwealth unless the person is sixteen years of age or older, (b) within one hundred and fifty feet of a swimmer, shore or moored vessel, except at headway speed, (c) on waters of the commonwealth of less than seventy-five acres, (d) without wearing an approved personal flotation device or (e), between sunset and sunrise. For the purposes of this section, the term, ''headway speed'', shall mean the slowest speed at which a personal watercraft, jet ski, surf jet or wetbike can be operated and maintain steerage way.