What is a disadvantage of a type 4 throwable PFD?

A disadvantage of a type 4 throwable personal flotation device (PFD) is that it requires someone to be able to reach and throw it to a person in distress, which can be challenging in rough water or if the rescuer is not close enough. Additionally, it may not provide the same level of buoyancy and support as wearable PFDs, leaving users vulnerable if they cannot quickly grab the device. This can limit its effectiveness in emergencies where immediate assistance is crucial.