Poijut

Poijut are navigational buoys deployed in marine environments to mark safe routes, hazards, and boundaries for ships and boats. The term is Finnish for buoys, and poijut can refer to various floating aids that help manage traffic, designate channels, mark hazards, or indicate mooring areas and research installations. Most are designed to float and are anchored or moored to the seabed, and many carry lights, radar reflectors, and sometimes AIS transceivers to aid recognition and tracking.

Design and markings: Buoys come in several common shapes and color schemes. The two traditional shape classes are conical "nun" buoys and cylindrical "can" buoys. In many regions, color and day-mark patterns communicate meaning: lighted buoys can show different colors; some buoys use red, green, or black-and-white patterns to indicate channel sides, dangers, or safe water. Day marks and reflective elements aid visibility in daylight, and lights improve recognition at night or in poor visibility.

Types and uses: Lateral marks mark the sides of navigable channels, guiding vessels on the correct side of the buoy. Hazard marks warn of wrecks, rocks, or other dangers. Cardinal marks indicate dangers relative to the cardinal directions. Safe-water marks denote open and navigable water. Buoys can be fixed to the seabed by anchors or mooring lines, or drift with currents for temporary or research purposes.

Management and regulation: Poijut are maintained by coast guards, port authorities, or hydrographic offices. Maintenance includes inspection, repainting, and replacement of lights or reflective elements. They are part of international navigation systems and are guided by organizations such as the International Association of Marine Aids to Navigation and Lighthouse Authorities (IALA).