An indication of an object on a display that does not correspond to the presence of an actual object at the point indicated.
Note: This term is also used for "Echo box" in U.S.A. (4-3-170).
Please note that this is the term as it stands in the original IALA Dictionary edition (1970-1989)
Celsius (previously Centigrade)
axis of the centre of water plane
International Association of Marine Aids to Navigation and Lighthouse Authorities - AISM