Sailing life jackets, or PFDs (Personal Flotation Devices), keep you afloat in a head-up position. They are available in foam vests or compact inflatable styles. PFDs for adults and juniors are sized by buoyancy weight and chest size. Some inflatable PFDs come with attachment points for a tether. Jacklines, tethers and harnesses are available for offshore sailing to ensure you always stay attached to the vessel. Most life jackets are U.S. Coast Guard approved, but buoyancy aids are not.