33 CFR §175.25

1. (a)This section applies to operators of recreational vessels on waters subject to the jurisdiction of any State that has established by statute a requirement for children of a certain age to wear an appropriate PFD approved by the Coast Guard, while aboard a recreational vessel.
2. (b)If the applicable State statute establishes any requirement for children of a certain age to wear an appropriate PFD approved by the Coast Guard, then that requirement applies on the waters subject to the State's jurisdiction instead of the requirement provided in § 175.15(c) of this part.