A life buoy is a floating ring designed to save someone who has fallen into water. You've probably seen these bright orange or red rings hanging on boats, docks, and pool sides. They're also called life rings or life preservers.

The buoy is made of buoyant material, meaning it floats easily and can support a person's weight in the water. If someone falls overboard or gets into trouble while swimming, you throw the life buoy to them. They can grab onto it and stay afloat until help arrives, even if they're tired or panicking. Most life buoys have a rope attached so rescuers can pull the person back to safety.

Modern life buoys often have reflective tape so they're visible at night, and some even have lights or whistles attached. Cruise ships and ferries are required by law to carry multiple life buoys for emergencies.

People sometimes use the phrase throw someone a life buoy to mean helping someone who's struggling, even when there's no actual water involved.