Is a characteristic of Type IV Personal Flotation Devices (PFD)?

Type IV Personal Flotation Devices (PFDs) are designed as throwable devices, such as cushions or rings, intended to be thrown to someone in distress rather than worn. They are typically used in calm waters and are not meant for continuous wear, which differentiates them from other types of PFDs. While they provide buoyancy, they require the person in distress to hold on to them, making them less effective for unconscious individuals. Type IV PFDs are often required on boats over a certain size as a safety measure.