The terms “life vest” and “lifejacket” are often used interchangeably, along with other terms such as PFD or buoyancy aid. Most usually, however, “life vest” refers to an inherently buoyant, foam-filled vest that provides competent swimmers with added flotation. They are intended for activities where users can reasonably expect to spend time in the water. “Lifejacket” often refers to an inflatable PFD, which has a lower profile, is more comfortable when dry, and uses a gas cylinder to inflate upon contact with the water. In an accidental overboard situation, they will right an unconscious person so that their face is above water.