Which class of vessel must have one type iv uscg-approved pfd on board in addition to one type you ii iii or v uscg- approved pfd for each person?

A class of vessel that must have one Type IV USCG-approved personal flotation device (PFD) on board, in addition to one Type I, II, III, or V PFD for each person, is a recreational vessel that is 16 feet or longer. The Type IV PFD serves as a throwable device, providing an additional level of safety for passengers in case of an emergency.