What is a disadvantage of a type iv throwable device pfd?

A disadvantage of a Type IV throwable device PFD (personal flotation device) is that it is not intended to be worn, which means it may not provide immediate buoyancy to a person in distress. In an emergency situation, retrieving and throwing the device can take valuable time, and it may not be readily accessible if the user is in the water. Additionally, it may not be suitable for all situations, such as swift water or rough conditions, where a wearable PFD would offer more reliable safety.