Alternative term: (Visual) Aid (to navigation), Seamark
An artificial or natural object of easily recognisable shape or colour, or both, situated in such a position that it may be identified on a chart or related to a known navigational instruction (e.g. taken from a List of Lights, etc.).
Note 1: This term includes buoys.
Note 2: A fixed artificial navigation mark is often called a Beacon. This may be lighted (2-5-005) or unlighted (2-6-030). The French term Balise is generally used to describe an unlighted beacon.
Note 3: In French, the term Amer Remarquable is applied to a navigation mark which is particularly easily seen, by virtue of its form, size or colour.
Please note that this is the term as it stands in the original IALA Dictionary edition (1970-1989)
acceleration due to gravity (m/s2)
International Association of Marine Aids to Navigation and Lighthouse Authorities - AISM