V Bottom – A hull with the bottom section in the shape of a “V”.
V flag + two numerals – Code flags; Speed in K.P.H.
Vailing Topsail – Letting go topsail halyards as a salute.
Valuation Clause – Inserted in a policy of marine insurance to cover cases when ship becomes a constructive total loss. Stipulates that insured value of ship shall be considered to be her value if repaired. If cost of repairing exceeded insured value the latter would be paid by insurers.
Valve – Mechanism that controls rate and amount of flow through an aperture.
Valve Metal – Red brass consisting of 80% copper, 8% zinc, 3 1/3% tin, and 2 1/2% lead.
Vane – Contrivance for indicating direction of wind. 2. Blade of a towed or submerged log. 3. Small flat plate used when sighting.
Vang – A down haul tensioning rope on a sail’s spar. A tackle between mast foot and the boom to stop it rising reducing twist developing in the upper sail.
Vangs – Ropes, one on either side of a gaff, by which the gaff is hauled into a desired direction, and held there.
Vapour – The gaseous state of a substance.
Variable Range Marker (VRM) – a RADAR feature that provides accurate measurements of range or distance to targets.
Variable Stars – Stars whose apparent magnitudes vary periodically. Algol is an example, its magnitude changing from 2nd to 5th magnitude in less than three days. Some of them are binary stars in which one star passes in front of the other; others are giant stars that undergo some internal change.
Variables – Airs and inconstant winds in sea area between N. E. and S. E. trades. Area is about 500 miles wide in September, decreasing to about 150 miles at end of year. Also ‘Variables of Cancer and Capricorn’.
Variation – The difference between a true and magnetic compass direction, due to the earth’s magnetic field not being consistently aligned with the poles.
Varnish – A transparent surface coating which when applied to natural wood coats it with glossy finish. A sludge that forms in fuel tanks when the fuel is allowed to stand over a long time and become stale.
Vas –. Usual contraction of ‘Avast’.
Vast – An order to stop.
V-bottom – A hull formed with V-section from chines to keel, that can plough through the waves.
V-drive – A gear box that reverses the direction of the drive train to allow the use of a standard prop shaft and prop with a rear mounted motor.
Vector diagram – A plot of directions and speeds, or set and drift, for facilitating leeway and current calculations.
Veer – The wind veers when the angle that it approaches the observer shifts in a clockwise direction. To veer cable is to ease out more anchor chain under control of the windlass brake. See also: Safe Anchoring Techniques – How to Drop the Ship’s Anchor Properly.
Veer and Haul – To pay out cable and then immediately to haul on it. Slack made by veering allows hauling machinery to pick up speed.
Veering – Applied to cable or hawser, means paying out. Applied to wind, means altering direction clockwise.
Vega – Star α Lyrae. S. H. A. 81°; Dec. N39°; Mag. 0.1. One of the ‘hydrogen’ stars, or A stars. Its diameter is 2 1/2 times that of Sun, its candlepower being 50 times greater. Is 26 light-years distant from Earth.
Vehicle – That liquid which carries the base and pigment of a paint.
Veiling Topsail – Vailing topsail.
Velocity – Speed. Usually expressed by units of distance travelled in a specified unit of time. The ‘knot’ is an unit of velocity, and does not require a time value.
Velocity of Light and Radio Waves – 186.285 statute miles per second. Is about 43 miles per second less in air. Approximately 11 million miles a minute. 161, 800 sea miles per second. 328 yards per microsecond. 300 million metres per second.
Velocity of Sound – In air is about 1090ft. per second at 32° F. (0°C) and increases 1.14 ft. per second for each degree F. (2.05 for degree C.) above. In water, velocity varies with salinity, temperature, and pressure (depth), but lies between 785 and 845 fathoms per second for small and great depths respectively.
Velocity of Translation – Speed of movement of a storm centre.
Velocity of Wave – Speed at which crest moves.
Vendaval – A moist and turbulent south-west wind of the Iberian Peninsula during November to April.
Vendavales – Squally SW winds in vicinity of Straits of Gibraltar between September and March.
Vent Pipe – Pipe placed to facilitate escape of air or vapour.
Ventilation – The positive changing of air within a compartment or space, whether produced by natural or mechanical means, through a system of air outlets, exhaust and ducts to induce a flow of air through the compartment or space.
Ventilator – Any arrangement that removes foul air from a space and supplies fresh air to it.
Ventilator Cowl – The rotating flange at the opening of a ventilator; a scuttle.
Venture – An enterprise in which there is a risk of loss.
Venus – Second planet from Sun, mean distance from him being 67, 200, 000 miles. Being an inferior planet it phases, and has a limited elongation of 48°. Distance from Earth varies between 26 and 160 million miles. May be observed in daytime occasionally.
Veranillo – A spell of fine weather, for about three weeks, during the summer rainy season in Central America.
Verano – Dry weather spell during winter in Central America.
Vernal Equinox – Spring equinox. The date, about March 21, when Sun crosses Equinoctial from south to north declination. Although this corresponds with autumn in the southern hemisphere, the name is fairly universal. The point where the sun moves northward across the equator each year.
Vernier – Auxiliary scale, close alongside principal scale, for reading fractional values of main scale by noting coincidence in alignment of graduations on vernier and main scale; the vernier graduation indicating the fractional value.
Vertex – The highest point in a curve. The zenith. That point at which a great circle track reaches its highest latitude. That point in any geometrical figure that is farthest from the base.
Vertical Band Width (VBW) – Radar term. The vertical width of the radar beam.
Vertical Centre of Gravity (VCG) – The height of the centre of gravity above the keel.
Vertical Circle – Any great circle, of the terrestrial sphere, whose plane is perpendicular to the horizon. It follows that all vertical circles will pass through the zenith.
Vertical clearance – Height above chart datum to the underside of an obstruction.
Vertical Keel – Continuous fore and aft plating resting vertically on a flat plate keel.
Vertical Sextant Angle (VSA) – used for determining distance off. Distance off = (Height of object, mtrs x 1852) ÷ S.A. in mins
Verticals – Short name for vertical circles of the celestial sphere.
Very High Frequency (VHF) – Radio frequency range from 30 MHz to 299 MHz.
Very Large Crude Carrier (VLCC) – Tankers of 200,000 to 320,000 dwt. They can carry 1.9 million to 2.2 million barrels of crude oil. Related Article: How to Identify Oil Tanker Sizes- Handymax, Panamax, Aframax, Supertankers.
Very Large Ore Carrier (VLOC) – Special categories of bulk carriers that weighs 380,000 to 400,000 deadweight tons.
‘Very Well Dice’ – Until comparatively recently was an order to helmsman to keep her head in the direction she then had. Now replaced by order ‘Steady’, or ‘Keep her so’. Related Article: Standard Helm Orders, Meaning and Execution.
Very’s Lights – Pyrotechnic signals, fired from a pistol, showing red, white, or green stars for signalling purposes.
Very’s Pistol – Pistol-type implement for igniting and ejecting a Very’s light.
Vesper – Name given to Venus when an evening star.
Vessel – Includes every description of water craft, including non displacement craft and seaplanes, sed or capable of being used as a means of transportation on water.
Vessel engaged in fishing – Any vessel fishing with nets, lines trawls or other fishing apparatus which restrict manoeuvrability, but does not include a vessel fishing with trolling lines or other fishing apparatus which do not restrict manoeuvrability.
Vessel Manifest – An international carrier is obliged to declare of the ship’s crew and contents at the port of departure and arrival in this document.
Vessel Traffic Management System (VTMS) – Vessel control system by a maritime authority for safety, protection of the environment and coordination of marine services.
Vessel Traffic Services (VTS) – Shore-side systems which range from the provision of simple information messages to ships, such as position of other traffic or meteorological hazard warnings, to extensive management of traffic within a port or waterway.
VHF Radios – Also known as Marine VHF Radio. It allows instant voice communication between ship-to-ship, ship-to-shore, and ship-to-aircraft with an effective range of 30 nautical miles.
Vice-Admiral – Flag officer next in rank above rear-admiral, and next below admiral.
Victory Ship – Fast cargo ships of World War II built in U. S. A.
Victualler – Small vessel employed in keeping a fleet of warships supplied with provisions.
Victualling Bill – Customs document allowing shipment of bonded victualling stores to an outward-bound vessel.
Victualling Yard – Naval storehouse that supplies provisions and other paymasters’ stores to ships of Royal Navy.
Vigia – Uncharted navigational danger that has been reported but has not been verified by survey.
Viol – Voyal.
Viol Block – Block having a cut-away part in shell so that a rope can be put over sheave. Similar to a snatch block but not having the hinged keeper.
Virazon – Spanish name for a sea breeze.
Virga – Precipitation that evaporates as it falls towards the ground.
Virgo – Constellation situated between R. A. 11 h 45 m and 14 h 10m, and Dec. 11° S and 12° N, approx. Contains bright star Spica, α Virginis. Also, sixth sign of Zodiac, extending from 150° to 180° celestial longitude. Sun is in this sign from August 23 to September 22 (about).
Vise – Endorsement on a document as evidence that it has been sighted, examined, and found correct by a proper authority.
Visibility – Of a light, given on charts, is the distance at which it can be seen on a dark night, with clear atmosphere, by an observer whose height if eye is 15 ft. above level of high water. Term used to express the clearness of the atmosphere and the maximum range at which objects and lights can be clearly sighted. Thirty-one miles is ‘excellent visibility’.
Visible Horizon – The boundary of Earth’s visible surface at the position of an observer. The circle in which it appears to meet the sky is below the sensible and rational horizons by an amount depending on height of observer’s eye above sea level.
Visitation and Search – The right of warships of a belligerent power to stop shipping, on the high seas or territorial waters of an enemy, for the purpose of searching them for contraband. No claim for loss or expense incurred by the searched ship can be made against the belligerent power for the reasonable exercise of this right.
Visor – An awning around the pilot house windows or air ports to exclude the glare of the sun or minimize rain or spray.
Visual Flight Rules (VFR) – governing procedures for conducting flight under visual meteorological conditions. In addition, used by pilots and controllers to indicate type of flight plan.
Visual Meteorological Conditions – Meteorological conditions expressed in terms of visibility, distance from cloud, and ceiling equal to or better than specified minima.
Voice Tube – A communication apparatus consisting of a tube that is spoken into from one part of the ship to another.
Voith Schneider Propulsion – The engine shaft passes vertically through the bottom of the hull and rotates a wheel to which paddles or blades are attached at right angles to the wheel. The attitude of the paddles, controlled from the bridge, can be changed to direct their thrust and the vessel is highly manoeuvrable. See Also: Types of Tugboats and Everything You Need To Know.
Volt – Volt is the unit of electrical pressure. It can be compared to the pressure from a pump in a piped water circuit.
Voltmeter – Instrument for measuring and indicating the voltage, or electromotive force, of an electrical current. Volts = Amps x Ohms
Volume of Displacement – Displacement of a vessel when expressed in cubic measurement.
Voluntary Stranding – Intentional and deliberate stranding of a vessel for the greater safety of ship and contents.
Vortex – The spiral pattern of matter as it swirls towards a central point.
Votive Ship – Model ship placed in a church or chapel as a thanksgiving for some danger escaped or as the fulfilment of a vow.
Voyage – In general, a journey by sea from one place to another, or to other places. In certain cases the voyage is considered as beginning when vessel arrives at her loading port, and ending when she has been moored in good safety at her discharging port for 24 hours. A longer journey. See Also: What is a Notice of Readiness or NOR?
Voyage Policy – Contract of marine insurance covering a voyage from one port to another, or others.
Voyal – Endless rope that was led round a capstan and through leading blocks to allow cable to be hauled by lashing the cable to the rope. Commonly used for hauling cable to locker when locker was some distance from capstan.
V-Shaped Depression – Depression in which the isobars form a series of parallel Vs with line of low pressure passing through the angles. Low pressure area is in direction of open ends of Vs.
V-Shaped Trough – V-shaped depression.
V-Sheet – Orange sheet signifying distress in Australian domestic waters.
V-Stern – A stem that has a more or less vertical, triangular transom plate.
Vulgar Establishment of Port – Interval between time of Moon s transit at a place, at Full or Change, and the occurrence of the following high water at the place.