Fog signals

The tags defined on this page will render in various nautical charts. This page defines tags for the attributes of fog signals.

Type	S100 code	seamark:type	Definition	Rendering
Fog signal	FOGSIG	fog_signal	A warning signal transmitted by a vessel, or aid to navigation, during periods of low visibility. Also, the device producing such a signal.

This page defines values for the "seamark:fog_signal:category" tags and other attributes applied to fog signals.

Category (CATFOG)	seamark:fog_signal:category	Definition
Explosive	explosive	A signal produced by the firing of explosive charges.
Diaphone	diaphone	A diaphone uses compressed air and generally emits a powerful low-pitched sound, which often concludes with a brief sound of suddenly lowered pitch, termed the 'grunt'.
Siren	siren	A siren uses compressed air and exists in a variety of types which differ considerably in their sound and power.
Nautophone	nautophone	A horn having a diaphragm oscillated by electricity
Reed	reed	A reed uses compressed air and emits a weak, high pitched sound.
Tyfon	tyfon	A diaphragm horn which operates under the influence of compressed air or steam
Bell	bell	A ringing sound with a short range.
Whistle	whistle	A distinctive sound made by a jet of air passing through an orifice.
Gong	gong	A sound produced by vibration of a disc when struck.
Horn	horn	A horn uses compressed air or electricity to vibrate a diaphragm and exists in a variety of types which differ greatly in their sound and power. The classification 'horn' is the generic term for fog signals `nautophone`, `reed` and `tyfon`.

Signal generation (SIGGEN)	seamark:fog_signal:generation	Definition
Automatically	automatic	Signal generation is initiated by a self regulating mechanism such as a timer or light sensor.
By wave action	wave	The signal is generated by the motion of the sea surface such as a bell in a buoy.
By hand	hand	The signal is generated by a manually operated mechanism such as a hand cranked siren.
By wind	wind	The signal is generated by the motion of air such as a wind driven whistle.

Attribute	seamark:fog_signal:<attribute>	Value type	Definition
Value of maximum range (VALMXR)	range	Decimal	The maximum range at which the signal can be heard in nautical miles.
Signal frequency (SIGFRQ)	frequency	Integer	The frequency of the sound signal, in Hertz.
Signal group (SIGGRP)	group	Text	The number of consecutive sounds, or the morse character(s) within one period of full sequence.
Signal period (SIGPER)	period	Decimal	Time of the time occupied by an entire cycle of intervals of sound and silence.
Signal sequence (SIGSEQ)	sequence	Text	The sequence of times occupied by intervals of sound and silence.

Seamarks/Fog Signals