46 CFR § 160.077-3 - Required to be worn.
(a) A Type V hybrid PFD may be used to meet the Coast Guard PFD carriage requirements of subpart 25.25 of this chapter, and 33 CFR part 175, only if the PFD is used in accordance with any requirements on the approval label. PFDs marked “REQUIRED TO BE WORN” must be worn whenever the vessel is underway and the intended wearer is not within an enclosed space.
(b) If hybrid PFD's with the marking “REQUIRED TO BE WORN” are not worn under the conditions stated in paragraph (a) of this section, other approved PFD's will have to be provided to comply with the applicable carriage requirements in 33 CFR part 175 and subpart 25.25 of this chapter.
(c) The following PFD's must be marked “REQUIRED TO BE WORN” as specified in § 160.077–31:
(1) Each Type V recreational hybrid PFD.
(2) Each Type V commercial hybrid PFD.