Sea mark
A sea mark is a pilotage aid which identifies the position of a maritime channel, hazard and administrative area to allow boats and ships to navigate safely.
There are two types sea mark :
- posts - fixed to the sea bed
- buoys - consisting of a floating object that is usually anchored to a specific location on the bottom of the sea or to a submerged object
Sea marks are used to locate channels, dangerous rocks or shoals, mooring positions, areas of speed limits, traffic separation schemes, submerged shipwrecks, and for a variety of other navigational purposes.
The International Association of Lighthouse Authorities defines several systems of marks specifying the shapes, colours and characteristic lights of buoys depending on their purpose. Marks sometimes carry bells or other sound signals.
See also: lightvessel, lighthouse
