Which pfd is desighed to be thrown to someone in the water?

The personal flotation device (PFD) designed to be thrown to someone in the water is called a throwable PFD, often referred to as a "throw bag" or "rescue ring." These devices are typically lightweight, buoyant, and have a strap or rope attached for easy retrieval. They are intended for quick deployment in rescue situations, allowing the person on shore or a vessel to throw the device to someone in distress. Examples include buoy rings and buoyancy cushions.