In pulse systems, a method of providing information by modifying the signal (at its source) so that the signal presentation on the display alternately appears and disappears or shifts along the time base, e.g. in Loran, a means for indicating that a transmitting station is not operating correctly.
Please note that this is the term as it stands in the original IALA Dictionary edition (1970-1989)
acceleration due to gravity (m/s2)
Centre of buoyancy
International Association of Marine Aids to Navigation and Lighthouse Authorities - AISM