The working principle of navigation marks mainly includes the following aspects:
Visual navigation marks: Visual navigation marks are fixed or floating navigation marks that are intuitively identified by sailors through their shape, color and light features. Visual navigation marks include lighthouses, light posts, beacons, light buoys, buoys, light ships, etc. For example, lighthouses are usually set near important waterways, with high-intensity light-emitting devices on the top. The light range is generally not less than 15 nautical miles, which is used to help ships determine their positions, determine the direction of navigation, and mark obstacles and dangerous areas in the waterway.
Fixing method of floating navigation marks: Floating navigation marks are generally composed of navigation marks, anchor chains and sinkers. Anchor chains are divided into saddle chains, long chains, short chains, half chains and shackles, and the buoys are fixed to the sea surface through these chains. The sinkers use the principle of negative pressure to prevent sinking into the muddy bottom of the water, ensuring that the buoys can remain stable in wind and waves.
Function of navigation marks: The main function of navigation marks is to provide safety information for various water activities. They mark the location of waterways, anchorages, shoals and other obstacles, indicate water depth and wind conditions, and direct traffic in narrow waterways. Navigation aids play an important role in supporting water transportation, fisheries, marine development and national defense construction.
Classification of navigation aids: According to the working principle, navigation aids can be divided into visual navigation aids, sound navigation aids and radio navigation aids. Visual navigation aids are the most important and basic navigation aids, widely set up in ports and inland rivers, including lighthouses, light posts, beacons, light buoys, buoys, etc.