Buoys

Buoys are floating markers that serve as navigational aids, hazard warnings, and data collection devices in marine and river environments. They are designed to remain at a set position relative to a chart, either by anchoring to the seabed or by mooring, and they may carry lights, sound signals, radar reflectors, or electronic beacons to aid mariners during the day and night.

Common types include navigation buoys that delineate channels and mark hazards, mooring buoys that provide fixed points for anchoring vessels, and weather or research buoys that collect meteorological and oceanographic data. Marker buoys may indicate safety zones, wreck locations, or speed limits. Drifting buoys float with currents and are used for data collection; they are released into the sea and tracked remotely.

Buoys are constructed to withstand marine conditions, typically using a flotation hull, ballast to maintain stability, and mooring gear such as anchors and lines or tethered anchors. Additional equipment may include lights, day shapes, bells or horns, radar reflectors, and, in modern installations, AIS transponders or solar panels to power sensors and transceivers.

Color, shape, and topmark schemes follow regional and international standards set by authorities such as IALA. These conventions help mariners interpret the buoy's purpose quickly. In addition to physical markers, many buoys are equipped with sensors that relay weather, wave, and current data to shore stations for navigation safety and climate research.