What does a Type IV life jacket signify?

A Type IV life jacket is specifically designed to be a throwable device, which means it is not intended to be worn like traditional life jackets. Instead, it serves as a safety aid that can be tossed to someone in distress in the water, such as a buoy or a floating cushion. It is classified as a "throwable" personal flotation device (PFD), and its primary function is to provide immediate assistance to someone who has fallen overboard or is in danger of drowning.

This type of life jacket is not meant for prolonged use or to be worn continuously, which distinguishes it from other types of life jackets that are designed to be worn at all times for better safety and security. Additionally, while other life jackets may have features for ensuring maximum buoyancy and turning the wearer face up, the Type IV is simply a supportive tool for rescue situations rather than a primary flotation device for individual use.