Buoys are floating devices used in water bodies to mark locations, provide navigation assistance, or indicate hazards. They are often brightly colored and can be made from materials like plastic or metal. Buoys can serve various purposes, such as signaling safe passage for boats or marking underwater obstacles. There are different types of buoys, including navigation buoys, which guide vessels through channels, and moorings, which help boats anchor securely. Some buoys are equipped with lights or bells to enhance visibility and safety, especially during nighttime or poor weather conditions.