How Life Jackets Work

Coast Guard Regulation

The Coast Guard regulates life jackets and other flotation devices in the United States. The Coast Guard has approved five different categories for personal flotation devices (PFDs):

  • Type I - Off-shore life jacket
  • Type II - Near-shore buoyancy vest
  • Type III - Flotation aid
  • Type IV - Throwable devices, such as cushions or rings
  • Type V - Special use devices, such as float coats and deck suits

Types I, II and III are the flotation aids most commonly worn by recreational boaters.


Generally, PFDs with lower numbers provide more buoyancy. A Type I, or an off-shore life jacket, will turn an unconscious person into a face-up position most of the time. In order to accomplish this turn, more buoyant material is positioned near the front of the life jacket, so that the jacket rolls users over onto their backs. Because of this, Type I devices are very bulky in the front.

Near-shore buoyancy vests (Type II) are less bulky but may not always turn a person face-up. Flotation aids (Type III) are the least bulky and are more comfortable for all-day use because the buoyant material is more evenly distributed around the vest. However, these devices require some effort on the part of the wearer to keep the head above water. While the aid may not turn the wearer automatically, it does help a user remain vertical and afloat.

When picking out a life jacket, it's important to consider these characteristics, as well as the types of boating that one will be doing. A Type I PFD is best for open, rough waters and can keep a person afloat for several hours if a rescue will be slow in coming. Type II and Type III PFDs are better for inland and calm waters, when a person can be pulled back aboard a boat fairly quickly. The flotation type classification can be found on the label of the device. In the next section, we'll take a closer look at qualifications to consider when selecting a life jacket.