33 CFR § 175.15 - Personal flotation devices required.
Except as provided in §§ 175.17 and 175.25:
(1) At least one wearable PFD is on board for each person;
(2) Each PFD is used in accordance with any requirements on the approval label; and
(3) Each PFD is used in accordance with any requirements in its owner's manual, if the approval label makes reference to such a manual.
(c) No person may operate a recreational vessel under way with any child under 13 years old aboard unless each such child is either -
(1) Wearing an appropriate PFD approved by the Coast Guard; or
(2) Below decks or in an enclosed cabin.