Glossary Of Lighthouse Terms for the Maritime and Pacific Regions
With thanks to the Nova Scotia Lighthouse Preservation Society (NSLPS) for the use of their text.
|Click here for an “alphabetically-sorted” glossary listing|
Aid to Navigation/Navigational Aid: Devices and structures used to assist navigation by mariners, which includes but is not limited to lighthouses. May also include a lightship, buoy, beacon, radio beacon, fog alarm, range marker, or any other structure or device, installed, built or maintained for the purpose of assisting the navigation of vessels.
Alternative Use: The non-navigational use of an authentic Lighthouse to preserve and generate support for the historic structure. This can also take place in a lighthouse that is still used for navigational purposes.
Automated: A Lighthouse which has been changed to operate without the aid of a keeper. A keeper may still be retained for maintenance and security.
Characteristic: The unique visual identity of a Lighthouse including the light exhibited and the individual features of the structure which allow mariners to tell one Lighthouse from another.
Decommissioned: A Lighthouse which no longer functions as a navigational aid because the light has been turned off or has been removed..
Destaffed: An automated Lighthouse that has had its resident or non-resident keeper removed. – see Unwatched
Imitation Lighthouse: A reconstructed Lighthouse that attempts to express basic Lighthouse features but does not represent an individual historic Lighthouse. Example: Saint John CG base.
Lighthouse: Enclosed tower originally designed with an enclosed lantern and built by a governing authority as an aid to navigation.
Lightstation: Light tower and associated buildings (dwellings, sheds, boathouses, fog alarm, etc.) and the land they occupy.
List of Lights, Buoys, and Fog Signals (aka LOL): Official Canadian government list of navigational aids along the coasts and inland waterways featuring brief descriptions and precise locations. Regular updates are published in Canadian “Notices to Mariners” (NOTMAR)
Navigational Aid/Aid to Navigation: Devices and structures used to assist navigation by mariners, which includes but is not limited to lighthouses. May also include buoys, radio beacons, fog alarms, etc.
Ornamental Lighthouse: A decorative structure suggestive of a Lighthouse but holds no historic value. Example: Amherst visitor information center.
Relocated Lighthouse: An authentic Lighthouse moved from its original location, except those moved a short distance due to erosion. Example: Anderson Hollow, NB.
Replica Lighthouse: A structure built to carefully reproduce an authentic Lighthouse, faithfully utilizing historic documentation. Example: Burntcoat Head, NS.
Unwatched Lighthouse: A light or lighthouse with no permanent manned presence. – see Destaffed
Barge: A cargo vessel, generally without power. ref: Navy Slang website.
Lighthouse Tender: One of many Coast Guard vessels on the East and West Coast and Great Lakes that maintained, supplied, and serviced the Aids to Navigation, including the lighthouses. Example: CCGS Estevan, CCGS Camsel, etc.
Flotsam: The wreckage of a ship or its cargo found floating on the sea or washed ashore. ref: USACE glossary
Jetsam: Objects floating in the water, which have been cast overboard. To throw something overboard is to “jettison” that thing. ref: Navy Slang website.
Pontil: The pontil, or punty, is a solid metal rod that is usually tipped with a wad of hot glass, then applied to the base of a vessel to hold it during manufacture. It often leaves an irregular or ring-shaped scar on the base when removed. This is called the “pontil mark.” ref: The Store Finder
Cornice: Ornamental overhang often found on lighthouses as a graceful decorative treatment below the lantern or gallery deck. May be a simple sweeping curve (ex. Pictou Bar, NS) or may include decorative elements such as ornamental brackets (ex. Cape Jourimain, NB). Sometimes separated from the shingled side of the tower by a plain strip of wood called a fascia.
Cupola: A roof in the form of a dome on the lantern of a lighthouse.
Diaphone: A powerful type of foghorn invented in Canada which produced a loud “blast” followed by a “grunt”. It used compressed air generated by a steam, gas or oil engine, usually housed in its own building.
Focal height: The distance from sea level to the center of the illuminating light.
Fogbell: A forerunner to the fog alarm. It was a hand, steam or mechanically-operated bell aparatus used in poor visibilty.
Gallery: Exterior walkway around the lantern.
Lens: Any glass or transparent material that is shaped to concentrate, magnify and focus light.
Lamp: The lighting apparatus inside the lens. (ie. oil lamp, kerosene vapor burner, electric light bulb).
Lantern: The exterior enclosure that protects the lens and lamp. Often confused with the lens or lamp, it is actually the top portion of the Lighthouse from the deck up.
Lantern Deck: The exterior walkway around the lantern deck which was used for cleaning windows and maintenance.
Light Room: The room directly below the lantern. Here the keeper stored tools, cleaning supplies, etc. The air and fuel tanks were located there.
Smoke Jack/Smoke Head: A special stack on top of older lanterns used to vent smoke from the lamps, sometimes taking the form of a round ball (ex. Seal Island, NS) or a chimney with a metal vane (ex. Head Harbour, NB).
Schmutzedecke: The sand filter we used on the lights not only caught bird crap, insects etc. coming off the roof but it also caught pathogens, bacteria, and some bad oxidized stuff from the ocean that landed on the roof too. The schmutzdecke was a biological zone that broke that material down . Adding chlorine bleach, as we were instructed to do, did not kill the pathogens but did kill off the schmutzdecke. We were also told to fill the filter right up with sand but in fact, long hydraulic retention of water above the filter permits development of a substantial biological community (in the schmutzdecke). Also, I we were told to regularly scrape off the top layer of the filter, which actually removed that essential part of the system.” Read more on it here from Wikipedia.
Annular: Shaped like a ring.
Catadioptric: Optical systems which involve both lenses and mirrors. The Catadioptric lights possess and advantage of 16.5% intensity over Catoptric. See Catoptric and Dioptric below
Catoptric: A light which uses a concave mirror for magnification. Often indicated in the List of Lights as “C”. They were common before widespread use of Fresnel lenses but continued in some lighthouses long after.
Concave: A surface that is curved like the inside of a circle.
Curtains: Curtains are placed inside the lantern to prevent the rays of the sun from injuring the lamp, or setting fire to combustible objects outside, within the focus of the lens. These were used during the day when the lamp was extinguished.
Dioptric: A light which uses a lens for magnification. This is usually a Fresnel lens with size often indicated as “D” (D,6= sixth order).
Drum Lens: A common variation of the Fresnel lens but lacking a central bullseye and having the form of an open cylinder or “drum”.
Eclipse: Partial to total darkening or obscuration of the light caused by the rotation of the lens as seen from seaward.
Fresnel: The lens invented by Augustin Fresnel in 1821 which consists of concentric ridges radiating outward from the central lens (bullseye), with prisms positioned at the top and bottom of the ridges to refract the light from the light source placed behind the central lens. A term normally used only when referring to traditional cut glass style lenses, although the Fresnel principle is also found in more modern glass or plastic lenses.
Holophotal: Causing no loss of light; – applied to reflectors which throw back the rays of light without perceptible loss. ref: The Free Dictionary
Lamp: The lighting apparatus inside the lens. (ie. Oil lamp, kerosene vapour burner, electric light bulb).
Lenticular: Shaped like a double convex lens or a lentil (bean) ref: Suny Upstate Medical University (glossary).
Mercury Vapour lights (M.V.): will under certain atmospheric conditions, show a greenish hue, rather than white, which might be how it is listed in the List of Lights.
Nominal Range: The nominal range of a light used as an aid to marine navigation is its luminous range in a homogeneous atmosphere in which the meteorological visibility is 10 nautical miles (i.e The distance at which a light can be seen in clear weather.) ref: List of Lights
Order: A measurement of the size of a Fresnel lens, with first order being the most powerful (and largest) and seventh order being the least powerful (and smallest):
Parabolic Mirror: A mirror formed in a precise curve to cause the incoming light rays to be focused at the same point in front of the reflector.
Racon/Radar Beacon: a device that, on receiving radar signals, transmits coded signals in response to help navigators determine their position.
Radar Beacon/Racon: a device that, on receiving radar signals, transmits coded signals in response to help navigators determine their position.
Radar Reflector: An object designed to increase the radio reflectivity of a daymark or buoy so that it is more visible on radar. Many aids to navigation are made with fiberglass, wood or plastic materials that do not reflect radar very well on their own.
Refracting: The ability of glass to make a ray of light change direction when it enters at an angle.
Equal-Interval (Isophase) Iso: A light for which the alternations of light and darkness are of equal duration.
Fixed: A continuous steady light. Abbreviated as “F”. A light which appears continuous and steady and of a constant colour.
Flash Pattern: ( a series of light flashes and eclipses (darkness) identify the light.
Flashing: A light in which the total duration of light in each period is clearly shorter than the total duration of darkness and in which the flashes of light are all of equal duration – i.e a light in which a flash is regularly repeated at a rate of 15 flashes per minute (a flash every 4 seconds) .5 sec. flash, 3.5 sec. eclipse. Abbreviated as “Fl4s”. ref: List of Lights
Group Flashing: A flashing light that combines flashes in groups of two or more, creating its own unique pattern or signal. Used to avoid confusion where several lighthouses are in close proximity. Abbreviated as “Gp.Fl.”
Long Flash: A light in which a flash of 2 seconds duration is repeated at a rate of 6 flashes per minute (a flash every 10 seconds) 2.0 sec. flash; 8.0 sec. eclipse; Abbreviated as “LFl 10s.”. i.e. Howard’s Cove Lighthouse characteristic is 2 sec flash, 4 sec eclipse for a cycle of 6 seconds.
Morse A: A light in which a short flash is followed by a long flash to form the letter “A” in the Morse Code 10 times per minute (every 6 seconds) 0.3 sec. flash; 0.6 sec. eclipse;1.0 sec. flash; 4.1 sec. eclipse; Abbreviated as “Mo (A) 6s”. ref: List of Lights
Occulting: A light in which the total duration of light in each period is clearly longer than the total duration of darkness and in which the intervals of darkness (occultations) are all of equal duration – i.e. a light that appears at regular intervals briefly interrupted by periods of darkness, which are shorter than the period of light. Abbreviated as “Oc”
Quick Flashing: A light that appears at regular intervals briefly interrupted by periods of darkness, which are shorter than the period of light. Abbreviated as “Q 1s”. ref: List of Lights
Very Quick Flashing: A light in which a flash is regularly repeated at a rate of 120 flashes per minute (a flash every 1/2 second) .2 sec. flash, .3 sec. eclipse Abbreviated as “VQ .5s”ref: List of Lights
Light Characteristics – A light’s characteristic is composed of:
For additional light characteristics check the introductory pages on the
Types of Lighthouses
Coastal Light: A medium sized lighthouse marking major coastal features such as capes, points and major islands. Example: East Point, PEI.
Daymark: The daytime characteristics and markings of a Lighthouse; also a signboard attached to a daybeacon to convey navigational information presenting one of several standard shapes (square, triangle, rectangle) and colors (red, green, orange, yellow, or black). Daymarks usually have reflective material indicating the shape, but may also be lighted, and which allow mariners to distinguish one lighthouse from another. ref: Boattalk dictionary
Harbour Light: A small lighthouse used to assist navigation within a harbour. Example: Neil’s Harbour, NS. Sometimes located on wharves or piers in which case they are known as wharf or pier lights.
Hazard Avoidance Light: A lighthouse used to mark a specific hazard such as a shoal, reef, rocky point or dangerous island. Example: Ile Haute, NS. Many lighthouses serve as both coastal and hazard avoidance lights.
Landfall Light: A large lighthouse first sighted as a mariner nears land. Example: Cape Sable, NS. – see Sea-Light
Leading Light: A lighthouse used as a landmark when fixing a course along a waterway. More commonly found as inland lights. Example: Sand Point, St John River, NB.
Range Lights: Two or more lights which indicate a safe course when lined up one above the other to form one or more leading lines (or ranges). Sometimes one or both may be simple skeleton towers but older range lights can often be fine heritage structures. Example: Leards Range, PEI (front & rear).
Sea-Light: A light situated on the coast, and intended to warn vessels approaching it of its proximity. – see Landfall Light
Sector Light: A light presenting different characters (usually different colours) over various parts of the horizon of interest to mariners – it indicates safe passage by a change in colour when the mariner moves off course. i.e: Wallace, NS. Another example: A light showing three different colours which is found at Leard’s Front Range Light.
ALC: Atlantic Lighthouse Council. A group of partners concerned with lighthouse development in the Maritime region.
CCG: Canadian Coast Guard. The agency traditionally responsible for the management of lighthouses and other aids to navigation, now a part of DFO.
DFO: Department of Fisheries and Oceans. The federal department responsible for active lighthouses and the fate of those they decommission.
Department of Marine: The predecessor of the Canadian Coast Guard beginning with Confederation and ending in the 1930’s.
FHBRO: Federal Heritage Building Review Office. The primary objective is to assist government departments in the protection of their heritage buildings owned by the federal government, which includes most lighthouses. To achieve this aim, they prepare extensive reports
Heritage Canada Foundation. A national organization and registered charity created in 1973 by the Government of Canada to preserve heritage places and to assist government departments in the protection of their heritage buildings and to encourage all Canadians to recognize, understand and care for the built heritage of Canada. To achieve this aim, they prepare extensive reports
IALA: International Association of Maritime Aids to Navigation and Lighthouse Authorities. An organization of governing bodies responsible for lighthouses in countries throughout the world.
LSNL: Lighthouse Society of Newfoundland and Labrador.
MCTS: Marine Control and Traffic Services, a department of the Canadian Coast Guard (CG) which has manned stations located on both Canadian coasts and also on the Great lakes. Their mission is to “provide communications and traffic services for the marine community and for the benefit of the public at large to ensure:
NBLHS: New Brunswick Lighthouse Society.
NSLPS: Nova Scotia Lighthouse Preservation Society.
PEILS: Prince Edward Island Lighthouse Society.
RPAM: Real Property and Asset Management. The branch of DFO which now manages lighthouse properties and oversees disposal.
Active lighthouse: One that is currently operating, be it manned or unmanned.
Beacon/Light Beacon: A lighted or unlighted fixed aid to navigation attached directly to the earth’s surface. (lights and daymarks both constitute beacons .)
Boatswain: This naval rating (pronounced “bosun”) involves many varied duties. Abbreviated BM. The term originally meant the “swain” or keeper of the boats, and the maintenance and handling of the ship’s boats is still charged to the boatswain and his apprentices. General ship’s maintenance, cargo handling, refueling, line handling, etc., are the province of the boatswain. ref: Navy Slang website.
Bow: The forward, (or, for landlubbers, the pointed end) of a vessel. ref: Navy Slang website.
Bridge: The command center, located high and forward on a vessel, in which the officer of the deck is stationed, and from which maneuvering orders are given. ref: Navy Slang website.
Cable: A nautical unit of horizontal distance defined as 0.1 nautical mile = 185.2 m. Historically, a cable was defined as equal to 600 ft (100 fathoms). ref: AMS Glossary website.
Chain: As a unit of measurement within the Imperial system, the chain is defined as 22 yards, 66 feet, or 4 rods. Ten chains made one furlong, and 8 furlongs to a mile means there are 80 chains to a mile. In metric units, a chain equals 20.1168 metres. A chain is divided into 100 links. ref: Wikipedia website.
EPIRB: Emergency Position Indicating Radio Beacon. An emergency device that uses a radio signal to alert satellites or passing airplanes to a vessel’s position. ref: Terrax Glossary website.
Fantail: Stern area of the main deck. ref: Navy Slang website.
Fathom: Nautical measure of length, equal to six feet. Usually used in measuring depth of water. A length of light line attached to a lead weight is dropped to the bottom and the result in fathoms announced. From this measure, the ship’s draft ,plus a safety factor, is subtracted to assure that there is sufficient water under the keel.ref: Navy Slang website.
Galley: The ship’s kitchen. ref: Navy Slang website.
GPS: Global Positioning System. A system of satellites that allows one’s position to be calculated with great accuracy by the use of an electronic receiver. ref: Terrax Glossary website.
Gunwale: (Pronounced “gunnel”) The above water edge of an open boat. In the case of a rowboat it is this edge into which are fitted the oarlocks or pintles Any time water comes over the gunwale in quantity, the boat is in jeopardy. ref: Navy Slang website.
Inside Lights: With reference to British Columbia Canada lighthouses, those situated on the Inside Passage between Vancouver Island and the mainland of British Columbia; those lighthouses not exposed directly to Pacific storms.
Larboard: The old name for the left hand side of a ship. It was officially changed to “Port” in 1844, to avoid confusion with starboard
Lee: On the side of the shipaway from the wind. Also, “Alee”, or “leeward”. The opposite of leeward is windward. ref: Navy Slang website.
Light Beacon/Beacon: A lighted or unlighted fixed aid to navigation attached directly to the earth’s surface. (lights and daymarks both constitute beacons .)
Nautical Mile: The 60th part of an equatorial degree, equal to about 6,080 English feet; therefore 6 nautical miles represent 7 English miles, approximately. ref: Liberty-Ship website.
Outside Lights: With reference to British Columbia Canada lighthouses, those situated on the outside of Vancouver Island and on the more exposed parts of mainland British Columbia; those lighthouses exposed directly to Pacific storms.
Painter: A light line used to make fast a boat to a ship or a pier. ref: Navy Slang website.
Phonetic Alphabet: The names for each letter of the alphabet which serves to reduce confusion in voice communication. e.g. Alpha=A, Bravo=B, etc.
Pier: A structure usually of stone or wood, projecting into navigable waters, to which a vessel may be secured for loading or unloading. ref: Navy Slang website.
Pile: A long column of timber driven into the ground to give a stable foundation for a structure to be built on.
Piling: A structure composed of wooden piles
Port: The left side of a vessel facing forward (see also Larboard)
Screw: The revolving fan-blade-like device located underwater astern which pushes a vessel through the water. Similar in shape and function to an airplane’s propeller, it may range in size from a few inches in diameter to several meters, and a weight of many tons. ref: Navy Slang website.
SCUBA: Acronym for “Self-Contained Underwater Breathing Apparatus”, which enables a sw a depth of 200 feet or more. ref: Navy Slang website.
Snotter: A length of rope or braided steel with a loop braided or fixed in either end and used for lifting or slinging.
Starboard: The right side of a vessel facing forward (see opposite Larboard). Ancient Viking longboats used one long steering oar always mounted on the right side of the vessel, thus this side was called the “steerboard”, which became starboard. ref: Navy Slang website.
Water Taxi: A water taxi is a boat used for public transportation. It could be a runabout or small fishboat, or other vessel, depending on the owner and location.
Collective Agreement: An agreement in writing between an employer and the union representing the bargaining unit which contains provisions respecting conditions of employment, fringe benefits, rates of pay and the right or duties of the parties to the agreement. Ordinarily, the agreement is for a definite period such as one or two years. ref: Ontario Hospital Association (OHA)
Memorandum of Understanding (MoU): A memorandum of understanding (MOU) is a legal document describing a bilateral agreement between parties. It expresses a convergence of will between the parties, indicating an intended common line of action, rather than a legal commitment. ref: Wikipedia
Treasury Board: The Treasury Board is responsible for accountability and ethics, financial, personnel and administrative management, comptrollership, approving regulations and most Orders-in-Council. (In other words, they set the pay scale for the jobs.) ref: Government of Canada
Gale Warning: A gale warning warns the public that sustained winds of 34 to 47 knots (39 to 54 mph) inclusive are expected or occurring, and are not directly associated with tropical cyclones. ref: NOAA.
MANCLIM (Manual of Climatological Observations) is available in PDF and HTML format
MANOBS: Acronym for MANual of OBServations. An online version is available here in PDF format
METAR: Acronym for METeorological Aerodrome/Airport Report which replaced the former Aviation Weather (SA). It is now the main observation code used in Canada to satisfy requirements for reporting surface meteorological data. Minimum reporting requirments include wind, visibility, present weather, sky condition, temperature, dew point, and altimeter setting.
WX: Common telegraph abbreviation for weather. It was used primarily with Morse code, but its use still continues even today. ref: Wikipedia
For additional weather abbreviations go to the Flight Plan Weather website.
ALAN: Automated Lightstation Alarm Network. Same as ALN and ALEN; just a different variation.
ALEN: Automated Lightstation Emergency Network. Same as ALN and ALAN; just a different variation.
ALN: Automated Lightstation Network. A VHF/UHF telephone network that was started in the 1970s to communicate with and control automated stations on the Pacific coast. (aka ALAN and ALEN)
ATON: Aids to Navigation
HF: High Frequency is the radio frequency spectrum between 3 MHz and 30 MHz.
Mayday: The official voice radio signal (since 1948) for distress. Modern radio practice is now mostly voice, as against the original Morse telegraphic code transmitted in dots and dashes. The long-standing Morse distress call is SOS; or, dot, dot, dot; dash, dash, dash; dot, dot, dot; still handy to know if voice transmission is not available. ref: Navy Slang website.
Roger: Commonly used word in aviation communications. Just like “10-4” in other types of communications, it means that the instruction has been understood. Also, to roger is to repeat the instruction as to make sure it has been clearly understood. ref: Air Odyssey
Ten-Four (10-4): Message received. ref: Wikipedia
UHF: The Ultra High Frequency spectrum is everything from 300 megahertz to 3.0 gigahertz. One of the bands within this spectrum is the TV UHF band, which goes from 470 megahertz (channel 14) to 806 megahertz (channel 69). ref: HDTV Primer
VHF: The Very High Frequency spectrum is everything from 30 megahertz to 300 megahertz. It is divided into many bands for different purposes (police, fire, aircraft, etc.). Two of the bands within VHF are: