Anchor Clinch. Alternative name for 'Inside Clinch'. Was often used when bending hemp cable to ring of anchor.
Anchor Flags. Small red, green and numeral flags used when anchoring or weighing. Red or green flag used on bridge to indicate which anchor is to be let go; numeral flag used forward to indicate to bridge the number of shackles out.
Anchor Ice.Ice, of any form, that is aground in the sea.
Anemometer. Instrument for measuring wind velocity or pressure.
Anemometry. Science dealing with measurement of wind pressures.
Anemoscope.Instrument for detecting wind and indicating its direction.
Aneroidograph. Aneroid barometer fitted with clockwork and a paper carrying a pen to give a continuous record of barometric pressures. Seamen usually call it a 'barograph', but this term included mercurial recording barometers.