HIPPING TERMS A abeam. See beam. abnormal magnetic variation. Designation applied to any anomalous value of the magnetic variation of which the cause is unknown. See also local magnetic anomaly. aboard. In the sense used in pilotage and ship handling means “near”. eg “To keep the Eshore aboard”. “Close aboard” means “Very near”. See also borrow. above. Uptide or upstream of a position. above-water. A shoal, rock or other feature is termed above-water if it is visible at any state of the tide. See also awash,dries, below-water. abrupt. Steep: precipitous. See also bold. abyssal or abysmal. Relating to the greatest depths of the ocean (literally, without bottom). abyssal gap. A narrow break, in aridge or rise, or separating two abyssal plains. abyssal hills. A tract of small elevations on the sea floor. abyssal plain. A flat, gently sloping or nearly level region at abyssal depths. accretion or deposition. The depositing of material on the bottom or the coast by water movement; the opposite to erosion (qv). advance. When altering course, the distance that the compass platform of a ship has advanced in the direction of the original course on completion of a turn (the steadying point). It is measured from the point where the wheel was put over. aeronautical radiobeacon. A radiobeaconprimarily for the use of aircraft. Usually abbreviated to “aero radiobeacon”. affluent. A tributary river or brook. afloat. Floating, as opposed to being aground. age of the Moon. The interval in days and decimals of a day since the last New Moon. age of the tide. Old term for the lag between the time of new or full Moon and the time of maximum spring tidal range. agger. See double tide. agonic line. a line joining points on the Earth’s surface where there is no magnetic variation. aground. Resting onthe bottom. aid to navigation. A device or system external to the vessel that is designed and operated to enhance the safe and efficient navigation of vessels and/or vessel traffic. Examples include buoys,beacons,lights, radio beacons, leading marks, radio position fixing systems. See also navigation aid. air draught. The height of the highest point of the vessel above the water−line. alongside.A ship is alongside when side by side with a wharf, wall, jetty, or another ship. amphidrome. A point in the sea where the tide has no amplitude. Co-tidal lines radiate from an amphidromic point and co-range lines encircle it. anchorage. Water area which is suitable and of depth neither too deep nor too shallow, nor in a situation too exposed, for vessels to ride in safety. An area set apart for vessels to anchor, such as: examination anchorage. One used by ships while awaiting examination. quarantine anchorage. A special anchorage set aside, in many ports, for ships in quarantine. safety fairway anchorage.An anchorage adjacent to a shipping safety fairway (qv). anchor buoy.Small buoy occasionally used to mark the position of the anchor when on the bottom; usually painted green (starboard) or red (port), and secured to the crown of the anchor by abuoy rope. angle of cut. The lesser angle between two position lines. aphelion. The point in the orbit of aplanet which is farthest from the Sun. See also perihelion. apogee.The point in the orbit of the Moon which is farthest from the Earth. See also perigee. approaches. The waterways that give access or passage to harbours, channels, and similar areas. apron. The portion of a wharf or quay lying between the waterside edge and the sheds, railway lines or road. arch. Geologically, a covered passage cut through a small headland by wave action. archipelagic apron. A gentle slope with agenerally smooth surface on the sea floor, particularly found around groups of islands or seamounts. arc of visibility. The sector, or sectors,in which a light is visible from seaward. area to be avoided. A routeing measure comprising an area within defined limits in which either navigation is particularly hazardous or it is exceptionally important to avoid casualties and which should be avoided by all ships, or certain classes of ship. arm (of a jetty, or similar structure). A narrow portion projecting from the main body. arm of the sea. A comparatively narrow branch or offshoot from a body of the sea. arming the lead. Placing tallow in the recess in the bottom of the sounding lead to ascertain the nature of the bottom. artificial harbour. A harbour where the desired protection from wind and sea is obtained from moles, jetties, breakwaters, and similar structures. (The breakwater may have been constructed by sinking concrete barges, vessels, or other suitable objects to form a temporary shelter.) artificial horizon. A horizon produced by bubble, gyro or mercury trough to allow measurement of altitude of celestial bodies. astronomical twilight. The period between the end of nautical twilight (qv) and the time when the Sun’s centre is 18° below the horizon in the evening, and the period between the time when the Sun’s centre is 18° below the horizon in the morning andthe beginning of nautical twilight in the morning. atoll. A ring-shaped coral reef which has islands or islets on it,the shallow rim enclosing a deeper natural area or lagoon; often springing from oceanic depths. atollon. A small atoll on the margin of a larger one. awash. A shoal, rock or other feature is termed awash when its highest part is within 0·1 m, or with fathoms charts within 1 foot, of chart datum (qv). awash at high water. May be just visible at MHWS or MHHW. See also dries, above-water. B back. The wind is said to back when it changes direction anticlockwise. backshore. That part of the shore whose seaward limit is the waterline of MHWS and whose landward limit is the extreme limit of wave action (such as occurs in onshore gales at equinoctial spring tides (qv)). backwash. Waves reflected from obstructions such as cliffs,seawalls or breakwaters, running seaward and combining with the incoming waves to cause a steep and confused sea. backwash marks. Small scale oblique reticulate pattern sometimes produced by the return swash of the waves on a sandy beach. See also ripple marks, beach cusps. backwater. An arm of the sea, usually lying parallel with the coast behind a narrow strip of land, or an arm of a river out of the main channel, and out of the main tidal stream or current. bank. Oceanographically,an area of positive relief over which the depth of water is relatively shallow, but normally sufficient for safe surface navigation. The term should not be used for features rising from the deep ocean. Also, the margin of a watercourse such as a river, lake, or canal. The right bank of a river is the one on the right hand when facing downstream. bar. A bank of sand, mud, gravel or shingle near the mouth of a river or at the approach to a harbour, causing an obstruction to entry. bar buoy. A buoy indicatingthe position of abar. barrier. An obstruction, usually artificial, in ariver. eg Thames Barrier. barrier reef. A coral reef,lying roughly parallel with the shore, but separated from it by a channel or lagoon. The distance offshore may vary from a few metres to several miles. basalt. Dark green or brown igneous rock, often in columnar strata. basin. An almost land-locked area leading off an inlet, firth or sound. Also, an area of water limited in extent and nearly enclosed by structures alongside which vessels can lie. Oceanographically, a depression more or less equidimensional in form, and of variable extent. tidal basin. A basin without caisson or gates in which the level of water rises and falls with the tide. Sometimes called an open basin. non-tidal basin. A basin closed by acaisson or gates to shut it off from open water, so that aconstant level of water can be maintained in it. Also called a wet dock. impounding basin. A basin in which water can be held at a certain level, either to keep craft afloat or to provide water for sluicing. turning basin. An area of water or enlargement of a channel in aport, where vessels are enabled to turn, and which is kept clear of obstructions such as buoys for that purpose. bathymetry. The science of the measurement of marine depths. Submarine relief. bay. A comparatively gradual indentation in the coastline, the seaward opening of which is usually wider than the penetration into the land. See also bight, gulf. bayou. Term used in Floridafor asmall bay, and in Mississippi and Louisiana for a waterway through lowlands or swamps, connecting other bodies of water, and usually tidal or with an imperceptible current. beach. Any part of the shore where mud, sand, shingle, or pebbles accumulate in a more or less continuous sheet. The term is not used to describe areas of jagged reef, rocks or coral. to beach. To run avessel or boat ashore. To haul a boat up on a beach. beach cusps. Triangular ridges, or accumulations, of sand or other detritus regularly spaced along the shore, the apex of the triangle pointing towards the water, giving a serrated form to the water-edge. beach ridges. The seaward boundaries of successive positions of beaches on seaward-advancing shores. The intervening depressions may be extensive and contain features such as lagoons, marshes or mangrove swamps,or be narrow and consist of sand. See also storm beach. beacon. A fixed artificial navigational mark, sometimes called a daybeacon in the USA and Canada. It can be recognised by means of its shape, colour, pattern or topmark. It may carry alight, radar reflector or other navigational aid. beacon tower. A major masonry beacon the structure of which is as distinctive as the topmark. beam: on the. An object is said to be on the beam, or abeam, if its bearing is approximately 90° from the ship’s head. beam sea. The condition where the sea and swell approach the ship at approximately 90° from the ship’s head. bearing:anchor bearing. The bearing of a shore object from the position of the anchor. check bearing.The bearing of an extra object taken to check the accuracy of a fix. clearing bearing. The bearing of an object, usually taken from achart, to indicate whether a ship is clear of danger. line of bearing. A ship runs on a line of bearing if she makes good a ground track on a constant bearingof an object. bed. The bottom of the ocean, sea, lake or river. Usually qualified, eg seabed, river bed. bell-buoy. A buoy fitted witha bell which may be actuated automatically or by wave motion. below-water. A shoal, rock or other feature is termed below-water or underwater if it is not visible at any state of the tide. See also above-water. benchmark. A mark,such as an arrow cut in masonry, a bolthead, or arivet fixed in concrete, whose height relative to some particular datum is exactly known. berm. An horizontal ledge on the side of an embankment or cutting to intercept fallingearth or to add strength. Also, a narrow, nearly horizontal shelf or ledge above the foreshore built of material thrown up by storm waves. The seaward margin is the crest of the berm. berth. The space assigned to or taken up by a vessel when anchored or when lying alongside a wharf, jetty, or other structure. to give a wide berth. To keep well away from another ship or any feature. bight. A crescent-shaped indentation in the coastline, usually of large extent and not more than a 90° sector of a circle. See also bay, gulf. bilge (or keel) blocks. A row of wooden blocks on which the bilges (or keel) of aship rest when she is in dock or on a slipway. bill.A narrow promontory. blather. Very wet mud, a feature of estuaries and rivers; of adangerous nature such that a weight will at once sink into it. blind rollers. When a swell wave encounters shoal water it is slowed and becomes steeper. If the depth or extent of the shoal or rock is sufficient to cause the wave to steepen markedly but not to break, the resulting wave is termed ablind roller. bluff. A headland or short stretch of cliff with a broad perpendicular face. As adjective: Having a broad perpendicular or nearly perpendicular face. boat harbour. An area of sheltered water in a harbour set aside for the use of boats, usually with moorings, buoys, or other facilities. boat house. A shed at the water’s edge or above a slipway for housing a boat or boats. boat slip. A slipway designed specifically for boats. boat yard. A boat-building establishment. bog. Wet spongy ground consisting of decaying vegetation, which retains stagnant water, too soft to bear the weight of any heavy body. An extreme case of swamp or morass. bold. Rising steeply from deep water. Well-marked. Clear cut. bollard. A post (usually steel or reinforced concrete) firmly embedded in or secured on a feature such as a wharf or jetty,for mooring vessels by means of wires or ropes extending from the vessel and secured to the post. A very small bollard for the use of barges and harbour craft may be called a “dollie”. boom. A floating barrier of timber used to protect a river or harbour mouth or to enclose aboat harbour or timber pound. Also, a barrier of hawsers and nets supported by buoys used in the defence of a port or anchorage. booming ground. A term usedmainly in Canadian waters,and similar to timber pound (qv) where logs are temporarily held and stored for making up into rafts. The area is usually enclosed by a boom to retain the logs. bore.A tidal wave which propagates as a solitary wave with a steep leading edge up certain rivers. Formation is most apparent in wedge-shaped shoaling estuaries at times of spring tides. borrow. In the sense used in pilotage means “keep towards, but not too near”, eg “To borrow on the E side of the channel”. See also aboard. bottom, nature of the. The material of which the seabed is formed, eg mud, stones. boulders. Water-rounded stones more than 256 mm in size,ie larger than a man’s head. brackish. Water in which salinity values range from approximately 0·50 to 17·00. breakers. Waves or swell which have become so steep, either on reaching shoal water or on encountering a contrary current or by the action of wind,that the crest falls over and breaks into foam. breaking sea.The partial collapse of the crests of waves, less complete than in the case of breakers,but from the same cause; also known as White Horses. breakwater.A solid structure, such as a wall or mole, to break the force of the waves, sometimes detached from the shore, protecting a harbour or anchorage. Vessels usually cannot lie alongside a breakwater. bridge. A narrow ridge of rock, sand or shingle, across the bottom of a channel so as to constitute a shoal or shallow. Structure erected over a depression, or over an obstacle such as abody of water or a railroad, to provide a roadway for pedestrians or vehicles. Movable bridges are usually swing bridges, or lifting or bascule bridges. Swing bridges may pivot about a point, either in mid-channel or on one bank. Bascule bridges may be single or double,depending on whether they lift from one or both banks. bridge-islet.An island which is connected to the mainland, or to alarger island,at low water, or at certain states of the tide, by a narrow ridge of rock, sand, shingle, or other material. broach to. To slew around inadvertently broadside on to the sea, when running before it. broadside on. Beam on (eg to wind or sea). broken water. A general term for a turbulent and breaking sea in contrast to comparatively smooth and unbroken water in the vicinity. brook. A small stream. brow. An arrangement of wooden planking to give passage between ship and shore when the ship is alongside. Also called a “gangway”. bubble curtain. A length of perforated submarine pipeline from which compressed air is released, forming bubbles on the surface which discourage the formation of ice. Bubble curtains may be found in Norwegian waters, particularly around marine farms andsmall craft harbours. building slip. A space in ashipbuilding yard where foundations for launching ways and keel blocks exist and which is occupied by a ship when being built. buoy. A floating,and moored, artificial navigation mark. It can be recognised by means of its shape, colour, pattern,topmark or light character, or a combination of these. It may carry various additional aids to navigation. See also lanby, light-buoy. buoyant beacon. A floating mark coupled to a sinker either directly or by a cable that is held in tension by the buoyancy of the mark. Its appearance above the water generally resembles a beacon rather than a buoy; it does not rise and fall with the tide; and it normally remains in avertical or near-vertical position. Formerly k
Posted on: Wed, 29 Jan 2014 09:55:52 +0000
Trending Topics
Recently Viewed Topics
© 2015