What is the purpose of a Type 4 throwable device?

The purpose of a Type 4 throwable device is to be thrown to someone in trouble in the water. This type of device is designed to provide quick assistance to individuals who may have fallen overboard or are otherwise in distress. Unlike personal flotation devices (PFDs), which are meant to be worn at all times for individual safety, Type 4 devices are typically unoccupied until needed, enabling a rescuer to toss them to a person in need of flotation support.

The effectiveness of a Type 4 throwable device lies in its design; they are often buoyant and easy to grab, allowing victims to hold on until they can be rescued. This can be especially critical in emergency situations where time is of the essence. The other options do not accurately reflect the intended use or function of a Type 4 throwable device. For instance, while providing buoyancy is relevant, that is not the primary function of this type of device as it is not meant for continuous wear and remains unused until an emergency arises.