Beat frequency oscillator
In superheterodyne reception, the adjustable oscillator which, when heterodyned with the output of the final intermediate frequency stage, serves to translate an A-1 signal to the audio frequency range.
Please note that this is the term as it stands in the original IALA Dictionary edition (1970-1989)
Centre of buoyancy
axis of the centre of water plane
International Association of Marine Aids to Navigation and Lighthouse Authorities - AISM