Maritime Dictionary – Everything that Starts with the Letter “P”

by | Last updated Nov 24, 2023 | Maritime Dictionary | 0 comments

P – Code flag; All to report aboard, the vessel is about to sail. By a fishing vessel, my nets are fast on an obstruction. Morse Code; ● ▬ ▬ ●.

P Code – High accuracy and restricted access code in GPS positioning.

Pacific Rim – The regions bordering the Pacific Ocean.

Packet – A ship carrying mails or dispatches. May also carry passengers and cargo. Sometimes applied to a passenger vessel on a regular run.

Packet Boat – ‘Packet.’

Packet Ship – ‘Packet.’

Pack-Ice – Numbers of large pieces of floating ice that have come together and lie more or less in contact.

Pad – Shaped timber put on top of a wooden beam to give required camber. 2. Large and cylindrical coil of spunyarn or nettle stuff.

Pad Eye – A metal eye permanently secured to a vessel’s structure.  A ring or eye fixed to the deck to which a block may be shackled. Alternate spelling is padeye.

Pad Piece – Pad (timber).

Paddle – To propel a boat by using a paddle. 2. To row with a short stroke and very little weight. 3. Short oar with a broad blade. Held with both hands and not shipped in crutch or rowlock. 4. Board, or float, of paddle-wheel.

Paddle Shaft – Steel shaft by which paddles are turned by engines. 2. Handle of a wooden paddle.

Paddle-Beam – Strong thwartship beam fitted before and abaft a paddle-wheel.

Paddle-Box – Casing over upper half of a paddle-wheel.

Paddler – Vessel propelled by paddles.

Paddle-Wheel – Circular skeleton framework that carries paddle-boards. Is turned by an engine, and so propels vessel.

Paddle-Wheel Effect – That effect of a screw propeller which tends to pull ship’s stern to one side of her course. Due to lower part of blade working in water more unyielding than that at upper part.

Paddy’s Purchase – Seaman’s scornful name for any lead of a rope by which effort is lost or wasted. ‘Paddy’s purchase, spunyarn over a nail.’

Paint – Coating applied by brush, roller or spray for surface protection or decoration.

Painter – Rope at stem of boat for securing it or for towing purposes. 2. Chain by which an Admiralty pattern anchor is secured in place. ‘Shank Painter.’

Painter’s Colic – Form of lead poisoning due to lead in paint getting into system of a painter.

Pair Trawler – One of twin trawlers that spread the same net over a wide track spacing.

Pall – Old form of ‘Pawl’.

Pallet – A flat tray on which goods can be stacked to facilitate their movement by the use of forklift trucks.

Pallium – Old name for nimbostratus cloud.

Palm – Leather or hide strip that goes round hand and has an iron disc for forcing a sailmaker’s needle when sewing canvas or roping it. The fluke of an anchor.

Palm and Needle Hitching – Series of half hitches made with sail-maker’s twine and a palm and needle.

Palm and Needle Whipping – Whipping, at end of rope, that has been finished off by bringing end of whipping twine down a cantline of the rope, under the next strand, up the next cantline, behind the next strand and down the cantline. Palm and needle are necessary.

Palm of Anchor – Flat face of fluke that provides a holding surface.

Palowa – Sailing craft of China Seas. Schooner rigged, whale-boat stern, about 70 ft. long.

Pampero – Line squall off Argentina and Uruguay. Marked by thunder, lightning and rain. It is associated with temperature drop, rain, thunderstorms and following colder conditions.

Pan – A spoken radiotelephony message prefixed with the word ‘Pan’ indicates that an urgent message concerning the safety of a vessel, aircraft or person is about to be made. (French “panne” broken down).

Panama Canal – Approximates nett registered tonnage, but has important differences.

Panama Canal Tonnage – Computation for tonnage of ships passing through the Panama Canal.

Panama Lead – Circular fair leads at ends of a ship. Necessary when being towed by shore locomotives in Panama Canal.

Panamax – A vessel designed to be the maximum dimension that will fit through the Panama Canal.

Pancake Ice – Small, circular sheets of newly-formed ice that do not impede navigation.

Pangaia – Mozambique vessel mentioned by Hakluyt. ‘Like a barge, with one matsail of coconut leaves. The hull sewed together with the rinds of trees, and pinned with wooden pins.’ A supercontinent that consists of all the Earth’s landmass.

Pan-pan – The international radiotelephony urgency signal. When repeated x 3, indicates uncertainty or alert, followed by nature of urgency.

Panting – A more or less rhythmic in and out movement of ship’s plating due to variations in water-pressure. Particularly noticeable forward when pitching.

Panting Beam – Beam placed athwartships to support shipside plating against panting stresses. Found forward of the collision bulkhead found athwartships attached to the panting stringers.

Panting Stress – Stress, due to water pressure variations, that tends to cause an in and out movement of ship’s underwater plating.

Parachute Flare – A pyrotechnic intended as distress signal for initial detection with a visibility range of 25 miles at night. The flare is fired 200mtrs into the air and float down slowly on a parachute.

Parachute Spinnaker – A billowing sail of light material used for sailing downwind.

Parallactic Angle – Angle between hour circle of an observed heavenly body and the arc of a circle of altitude intercepted by the body and observer’s zenith. Is angle X in PZX triangle. Also called ‘Angle of Position’.

Parallactic Inequality – Variation in tidal phenomena that is due to variation in Moon’s distance from Earth.

Parallax – Apparent change in position of an observed object when due to change in position of observer.

Parallax in Altitude – Difference between altitude of heavenly body above sensible horizon and its altitude above rational horizon. Is maximum when body is in sensible horizon.

Parallel Circuit – A parallel circuit has the components connected in parallel, one beside the other, with the same wires going to each.

Parallel Index – Lines parallel to the bearing-marker on a radar display, useful for passing an intended distance from a point of land or vessel.

Parallel Middle Body (LP) – This is the length over which the midship section remains unchanged.

Parallel of Altitude – Small circle parallel to plane of horizon and passing through all points having the same altitude.

Parallel of Declination – Small circle of celestial sphere that passes through all points having the same declination.

Parallel of Latitude – Small circle of terrestrial sphere, parallel to Equator, passing through all positions having the same latitude.

Parallel of Position – Name sometimes given to a ‘Circle of Equal Altitude’.

Parallel Ruler – Twin rulers hinges side by side that can be used to walk from one line on a chart to another that is parallel. Used for plotting a position or a course line on a chart

Parallel Sailing – The sailing of a vessel along a parallel of latitude. Course will be East or West true. Difference of longitude will be distance run, in miles x Secant of Latitude.

Parallel Sphere – Terrestrial sphere as it appears to an observer at the Poles. All heavenly bodies appear to move parallel to horizon.

Paranthelion – Mock sun occasionally seen at same altitude as Sun but more than 90° away from it in azimuth.

Paraselene – Mock moon occasionally seen 22°-25° away from Moon in azimuth.

Paravane –. Torpedo-shaped body with transverse and inclined plate. Towed from bows of ship as a protection against moored mines. A hydrofoil dragged in mine clearance to drag a wire away from the minesweepers hull. Twin hydrofoils hung from a trawlers side booms to stabilize and reduce rolling.

Parbuckle – Simple two-power purchase made by securing bight of a rope and pulling upwards on the two ends. Any object of circular section can be laid in bights of loops, and will roll over as it is lifted. To parbuckle is to lift with a parbuckle.

Parcel – To wrap canvas, hessian, etc., tightly around the lay of the splicing in a rope preparatory to serving. Put on in direction of lay. 2. Separated part, of cargo, which is all of one nature, or is for one consignee, or for one port.

Parcelling – Material used for parcelling a rope.

Parhelion – Mock sun frequently observable in high latitudes. One is to be seen at 22° away from either side of true Sun, and is surrounded by halo or halos.

Parrel – Rope or collar by which the jaws of a gaff or yard are held to a mast. Rollers that attach a yard arm or boom to a mast while allowing its height to be adjusted.

Parrel Trucks – Large wooden balls threaded on a rope parrel to prevent parrel gripping mast when hoisting or lowering.

Parrotfish – Tropical fish with a mouth like a parrot’s bill.

Parson’s Turbine – Reaction turbine in which rings of blades on rotors are increased in size along path of steam, so allowing for expansion of steam.

Part – To separate, or to break, a rope or cable.

Part Brass Rags – R. N. term signifying to break a friendship.

Partial Awning Deck Type – Describes vessels having continuous deck and side plating from amidships to forecastle.

Partially Smooth Waters – Sheltered waters where the significant wave height does not exceed 1.5 m from trough to crest for at least 90 per cent of the time.

Particular Average – Indemnity due from a particular person or persons to make good a particular maritime loss against which insurance has been effected.

Particular Average Loss – Maritime loss that is indemnified by particular average.

Particular Charges – Expenditure incurred in averting a particular average loss; salvage and General Average charges being excepted.

Particular Lien – Legal claim upon certain property for money expended in connection with the property.

Parting Strop – Strop inserted between two hawsers, and weaker than the hawsers, so that strop, and not hawsers, will part with any excessive strain. 2. Special strop used for holding cable while parting it.

Partners – Fore and aft stiffeners on underside of deck to strengthen it in way of piercings of deck for masts, capstan spindle, etc. Supporting deck beams housing a mast or deck structure.

Pass a Line – To send a line to another vessel or ashore.

Pass a Stopper – Holding the strain on a line with a stopper to transfer between make fast points.

Passage – Narrow channel 2. Conveyance by ship. Sailing from one port or place to another.

Passage Boat – Boat that conveys goods and passengers.

Passage Broker – Person who is licensed by Government to sell or let steerage passages from U. K. to places outside Europe and Mediterranean Sea. Is required to give a bond to Government, and may employ agents approved by Emigration Officer.

Passage Money – Money paid for conveyance by ship.

Passage Winds – Trade winds, especially the ‘Westerlies’.

Passe Volant – A ‘Quaker’ or dummy gun.

Passenger – Any person other than Master, owner, owner’s family or owner’s servants, who is carried in a ship. Used sarcastically to denote a member of crew who does not pull his weight.

Passenger Ship – Vessel carrying fare-paying passengers.

Passenger Steamer – A steamer carrying more than 12 passengers.

Passing Ship – Said of a vessel going in a direction opposite to that of one’s own ship.

Patache – French name for a small sailing vessel used as a tender.

Patent Anchor – One that can be partially winched up into the hawse.

Patent Log – A trailing impellor log. See Walkers patent log.

Patent Log – Former name for a towed log. Such as a Cherub Log protected by patent.

Patent Slip – A slipway using a railway and cradle.

Path – That direction and route that a cyclonic depression may be expected to take.

Paul – Until fairly recently was the common spelling of ‘Pawl’.

Paunch Mat – Protective mat made by entwining strands of rope so that a thick mat with close-laid surface results.

Pavo – ‘Peacock.’ Southern constellation between Fomalhaut and Antares. Has one navigational star.

Pawl – Short, pivoted bar, with shaped toe, that trails over a toothed rack while machine is in motion. Pawl drops behind tooth of rack, by gravity or operation of a spring, and prevents reverse movement when moving power ceases.

Pawl Bitt – Vertical timber opposite middle of windlass. Carries pawl engaging in ratchet wheel on barrel.

Pawl Post – ‘Pawl Bitt.’

Pawl Rack – A well-secured series of standing stops against which a pawl can take.

Pawl Rim – Toothed wheel surrounding barrel of windlass, and in which a pawl engages.

Pay – To cover the caulking of a seam with pitch or marine glue. Monetary remuneration for work done.

Pay a Seam – To fill a join between planks with pitch.

Pay Away – To pay out a rope more quickly.

Pay Down – To pass a cable or hawser below deck.

Pay Off – To discharge a crew and close Articles of Agreement of a merchant ship. 2. To terminate commission. 3. Said of ship’s head when it moves away from wind, especially when tacking.

Pay Out – To veer a rope or cable. To allow a cable or rope run out. To receive settlement of wages due at the voyage end.

Paying Off Pendant – Very long pendant flown by H. M. ship when proceeding home to pay off. Length may be anything up to one foot for every month in commission, plus length of ship.

Pazaree – Rope, from clew of foresail, rove through block of lower studdingsail boom when running free.

Pea – Extremity of arm of anchor. Bill, or peak, of anchor. Related Article: Parts of an Anchor and Its Windlass Arrangement.

Pea Jacket – Loose jacket, of coarse woollen material, formerly used by seamen and fishermen.

Peak – After upper corner of spanker or trysail. After end of gaff. The summit of a hill or mountain.

Peak Downhaul – Rope rove through block at end of gaff to steady gaff when hauling it down.

Peak Halyards – Rope or purchase used for hoisting peak of gaff. 2. Ensign halyards rove through block at peak of gaff.

Peak Purchase – Peak halyards when rove as a purchase.

Peak Tank – Ballast tanks in extreme end of vessel, either forward or aft.

Peak Tye – Tye rove for hoisting peak of gaff. Pegasus. Northern constellation on side of Pole opposite to Ursa Major. Distinctive feature is the ‘Great square of Pegasus’ made by Alpheratz, Scheat, Markhab and Algenib.

Peaks – Enclosed spaces at each end of the vessel.

Peg to Windward – Beat, claw or work to windward. See ‘Traverse Board’

Peggy – Merchant Navy nickname for seaman whose turn of duty it is to keep the messing place clean.

Pelagi –: Performed on the open sea.

Pelican Hook – Name sometimes given to a slip hook. A hook with a sprung quick release gate latch.

Pelorus – Dumb compass dial, pivoted and movable by hand, which can be shipped in an appropriate position for observing bearings of objects obscured at compass. Has its own lubber line. Objects observed when pelorus is set to zero will indicate their relative bearings; when set to ship’s course they will indicate compass bearings.

Pelorus Jack – A white dolphin, about 15 ft. long, that persistently accompanied steamships through French Passage in Pelorus Sound, New Zealand, from the 1870s to 1912. His age has been estimated as nearly 300 years. Was a unique specimen, and his life was protected by legislation of New Zealand Government. A report of his death resulted in flags being flown at half mast in Wellington.

Penalty Clause – Clause attached to an agreement to stipulate penalty for infringement or non-fulfilment, so making it binding.

Pencel – Very small, narrow flag.

Pendant – Length of rope or wire connecting the standing block of a purchase with a fixed point of attachment. Used in derrick guys, at booms, yardarms, etc. 2. Alternative form of ‘Pennant’. Related Article: What are Fire Wires or Emergency Towing-Off Pennants?

Pennant – Four-sided flag with a head deeper than the fly, the upper and lower sides sloping towards the middle line. Usually spelt ‘pendant’, but this is open to criticism.

Pentad – Period of 5 days. Used in meteorology as being an aliquot part (1/73) of a year.

Pentekontor – Ancient Greek vessel of about 700 B. C. propelled with 50 oars.

Penumbra – Modification of an eclipse by the formation of a partly-illuminated area, or penumbra, between the lighted and eclipsed areas. In eclipse of Moon, it is due to sunlight being refracted by Earth’s atmosphere and falling on some of Moon’s eclipsed part.

People – Old name for a ship’s company.

Per Diem – By the day.

Perch – Vertical pole erected as a navigational aid and carrying a distinctive topmark.

Performance Monitor – A device for testing the performance of a radar set and indicating the result.

Perforst Men – Seamen taken out of a merchant ship for service in the Royal Navy. Corruption of ‘per force’.

Perigee – That point, in orbit of a solar system body, particularly Moon, at which it comes nearest to Earth.

Perihelion – That point, in orbit of a solar system body, at which it comes nearest to Sun.

Perils of the Sea – In policies of insurance and in bills of lading it denotes fortuitous accidents and casualties due to the sea. Does not include ordinary action of winds and waves.

Period of Encounter – Time interval between successive wave crests passing a given point in a vessel.

Period of Roll – Time, in seconds, taken by a vessel to roll from extreme angle on one side to extreme angle on opposite side.

Period of Wave – Time interval, in seconds, between passage of two wave crests past a stationary point. With ocean waves, this interval, in seconds, is about 2/7 speed of wave in knots.

Periodic Month – ‘Tropical Month.’

Periodic Wind – ‘Monsoon.’

Periodical Comet – Comet whose orbit is around Sun, and so reappears at intervals.

Periodical Meteors – Meteor showers, that occur at more or less constant intervals. More precisely, interstellar debris lying in Earth’s orbit and becoming incandescent when subjected to friction of Earth’s atmosphere.

Periodical Stars – Variable stars whose magnitudes change during a certain period.

Periodical Survey – Survey of a ship every four years in accordance with international regulations.

Periplus, Peripli – Voyage or voyages, or sailing directions, of the ancient Greeks.

Periscope – Long, slender prismatic telescope fitted in submarines for observing surface vessels while submarine is submerged.

Periscope Depth – That submersion of a submarine that leaves only the periscope above sea level.

Permanent Aurora – Slightly illuminated area in the night sky that is sometimes observable. Caused by ultra violet radiation of Sun in upper reaches of atmosphere.

Permanent Magnetism – That magnetism that is retained in whatever position the magnetised body occupies in a magnetic field.

Permanent Wind – Wind that blows in one direction continuously. Found between latitudes 20° and 40°N approximately.

Permeability – Property of soft iron to receive magnetism. 2. Capacity of a space to allow entry of water, having due regard to contents of the space.

Pernavigate – To sail over, or through.

Perpetual Day – Protracted interval during which Sun’s diurnal movement does not effect length of day. Maximum period, at Poles, is about six months.

Perpetual Night – Protracted interval during which Sun’s diurnal movement does not effect length of night. Maximum period, at Poles, is about six months.

Personal Equation – Factor or errors, more or less constant, that is to be ascribed to the personal qualities and limitations of the person responsible for an observation, deduction or result.

Personal Error – Error due to personal equation.

Personnel – Comprehensive term for all persons collectively in an undertaking, thus differentiating them from the ‘material’.

Personnel Flotation Device (PFD) – A device that keeps the wearer afloat and prevent them from drowning. Examples are lifejackets, lifering, life vests, etc.

Perspective Glass – Old name for telescope.

Perturbation – Irregularity or disturbance in a planet’s movement when due to forces not normally affecting it. 2. Variation in magnetic phenomena when due to eruptions or atmospheric electricity.

Peruvian Current – Ocean current, about 150 miles wide, setting from Valdivia and along coast towards Panama. Divides in vicinity of Payta.

Pescod Wing Fin – Horizontal and curved fin that is fitted a little below centre line of propeller shafting to give a good direction to water flowing towards propeller.

Peter Boat – A double-ended boat.

Petrol Engine – Uses the ignition of a petroleum and air mixture as a fuel.

Pett’s Disengaging Gear – Boat releasing gear in which boat is held on two horizontal hooks in fore and aft line of boat and at a greater distance apart than are the falls. Wire fore and after between lifting eyes on hooks keeps eyes in position; hooks have bill uppermost, and bill has a slight upward cant. After hook is hinged and controlled by lever, which can be locked in position. When after hook is. canted by lever the after block slips off, forward block then slips off. Boat drops into water slightly stem first.

Petty Average – The small expenses and charges borne by a vessel when entering a port to load or discharge. Generally referred to as ‘Average Accustomed’.

Petty Officer – Rank intermediate between officer and rating, and in charge of ratings. Usually messed apart from ratings, and has special privileges appropriate to his position.

Phact – Star α Columbae. S. H. A. 275°; Dec. S34°; Mag. 2.8.

Phantom Ship – ‘Flying Dutchman.’ There are, however, other phantom ships that are reported as having been sighted.

Pharos – A lighthouse or beacon. So called from the island of Pharos, in Bay of Alexandria, on which the first lighthouse was built by Sostratus Cnidius in 3rd century B. C. Was 450 ft. high and lasted for over 1000 years.

Phase – Appearance of Moon, or inferior planet, whose illuminated surface varies with its position relative to Sun and Earth. Mars, also, has a slight phasing. 2. Particular stage in recurring sequence of movements or changes usually expressed in degrees, the complete sequence or period being 360°. 3. Changes in a navigational beacon light in one period of exhibition.

Phase Inequality – Variation in tidal interval, or amplitude, between successive high waters as Moon goes through her phases.

Phase Lag – Lag, in time or angle, between exertion of a tide producing force and the appearance of its effect.

Phoenicians – Renowned ancient seafaring civilisation originating from the east Mediterranean.

Phonetic Alphabet – International radiotelephonic names for letters of the alphabet.

Phosphorescence – Bioluminescence. Luminosity of sea surface due to minute animal organisms in the water.

Phytoplankton – Microscopic floating plant life of the ocean.

Pick – Name sometimes given to pea of anchor. Colloquial name for an anchor.

Picket Boat – Fast, decked and mechanically-propelled boat carried in first class ships of R. N.

Picking Up Rope – Comparatively small rope carried from an arrived ship to a buoy, to hold ship while stronger moorings are attached.

Pier – Erection projected from land into water to form a landing, loading and discharging place; for a promenade or for protecting a port or harbour from effect of heavy seas. 2. Supporting member for an arch or span.

Pierhead Jump – The boarding of a vessel almost at the moment of sailing.

Pig – A piece of metal ballast. A device inserted into a pipeline that is used to maintain, inspect, clean, or clear its insides.

Pig and Whistle – Crew persons’ bar.

Piggin – Very small wooden pail having one stave prolonged to form a handle. Used as a bailer in a boat.

Pigging – Pipeline pigging. Using a device known as “pigs” to maintain, inspect, clean, or clear a pipline.

Pigs, Pig Iron – Lumps of iron used for ballast.

Pile – A strong post driven into the sea- or river-bed to mark the edge of the channel or to serve as a mooring.

Pile Driving – Said of a ship when, in heavy weather, she lifts her forefoot out of the water and it falls heavily into the sea.

Pile Up – To run a vessel ashore, or aground on a reef or rock. Pilferage. Petty theft. Pillars. Vertical members, of a ship’s construction, by which decks and beams are supported and the transverse form of vessel is maintained in the vertical plane.

Pillar Sextant – Type of sextant in which rigidity of frame is attained by having a rather massive vertical member.

Pillow – Wooden block on which inner end of bowsprit rests.

Pilot – Qualified person authorised to pilot incoming and outgoing vessels in a pilotage area. 2. One who controls a vessel. 3. Volumes of the Admiralty Sailing Directions, e. g. ‘The Mediterranean Pilot’.

Pilot Boat – Small craft used for embarking or disembarking pilots in sheltered waters.

Pilot Cutter – Sea-going vessel that cruises in a specific area for purposes of putting pilots on board inward bound ships, and for receiving them from outward bound ships.

Pilot Fish – Fish, about a foot long, sometimes seen preceding a shark. Bluish in colour with five to seven dark bars. May sometimes attend a ship.

Pilot Flag – Distinctive flag of a pilot vessel. Small replica may be flown by a piloted vessel. British flag is square with upper half white and lower half red.

Pilot House – The enclosed space on the bridge from which a ship is controlled.

Pilot Jack – Union flag with white border. Was used as request for pilot’s services.

Pilot Ladder – A rope ladder provided for a pilot to embark and disembark safely. It has spreader placed throughout to keep it from twisting. Related Article:  Different Ladders Intended for Use Over Ship’s Side.

Pilot Line – Astronomical position line along which a vessel can conveniently sail in good safety.

Pilot Signals – Signals made by a vessel requiring a pilot. International Code flag G, or at night, a blue light, or ‘G’ by flashing.

Pilot Station – Position, at sea or ashore, at which pilots are stationed for embarkation on vessels requiring pilotage.

Pilotage – Service duties, remuneration, fees or establishment of a pilot or pilots. 2. Navigation of ship by methods that do not require celestial observations. The process of navigating inshore waters.

Pilotage Authority – Corporate body, approved or appointed responsible for the organisation and conduct of pilotage in a given port or area.

Pilotage District – Area controlled by a particular Pilotage Authority.

Piloting – Navigation by use of visible references, the depth of the water, etc.

Pilot’s Fairway – Channel in which pilotage is compulsory.

Pilots’ Water – Any area, of sea or harbour, in which pilotage is compulsory.

Pin – Belaying pin. Axis of sheave or roller. Keep pin. Small and thin metal strip, or rod used for securing.

Pin Rack – Rack carrying belaying pins.

Pin Rail – Horizontal rail, at ship’s side, carrying belaying pins.

Pinch – To sail very close to the wind with some loss of speed.

Pinch Bar – Iron or steel lever with curved or inclined end and a tapered extremity, or toe. Toe forms lifting end, and curve, or angle of bevel, acts as fulcrum; thus giving considerable leverage.

Pineapple Knot – Ornamental knot that may have practical uses. Has appearance of an elongated ‘turk’s head’. Related Article: Can You Knot? 10 Widely Used Knots on Merchant Ships.

Pingle – Name formerly given to a small sailing craft of northern England. Probably connected with ‘Pink’; a little pink.

Pink Stern – A high and narrow stern.

Pink, Pinkie – Narrow sterned sailing craft with lateen rig. Stern projected aft considerably. Used for reconnoitring, carrying stores, and similar purposes.

Pinkney – See ‘Coiling & Pinkney’s Topsail’.

Pinnace – Formerly, small, two-masted sailing vessel sometimes with oars. Now rowing, sailing or mechanically-propelled boat of R. N. Is diagonal built; 36 ft. in length.

Pintle – Vertical pin, on forward edge of rudder, that ships into gudgeon and forms a hinge. Related Article: Types of Ship Rudders, Their Parts, and Profiles.

Pinyano – Small, one-masted fishing vessel of China Sea. Fitted with outrigger.

Pioneer – Net-cutting attachment formerly fitted into nose of torpedo to cut through torpedo-nets.

Pipe – To call seamen, or to direct them, by sounds on a boatswain’s call or pipe.

Pipe Berth – A bed constructed of a metal pipe frame stretching a canvas base.

Pipe Down – Order to boatswain’s mate to pipe hands ‘down from aloft’. Now used, in R. N., to inform hands that they will not be required for work; or, at night, that hands are to turn in. 2. Be quiet.

Pipe Stool – Shaped support in which a pipe rests.

Piping the Side – Naval courtesy paid only to specified naval officers, in uniform, boarding or leaving one of H. M. ships during daylight hours. Consists of two calls on boatswain’s pipe—one on approach to ship of visiting officer, the other as officer enters ship. Similarly, but in reverse order, as he leaves it.

Piracy – Robbery from a ship. The forcible taking of a ship, her cargo, apparel or furniture from the possession of the owner and for private gain. Also, the forcible entry into a ship for the purpose of damaging her.

Piragua – Large canoe of Central America.

Pirate – A thief on the sea. A person who attack and robs a ship in the sea.

Pirates – Robbers of a ship, not necessarily on the high seas. Includes mutinous passengers, and robbers who attack from the shore.

Pirogue – Form of ‘Piragua’.

Pitch – Dark-coloured solid obtained from distillation of tar. Has a low melting point and is insoluble in water. Used for paying of deck seams and stopping of small leaks.

Pitch of Propeller – Distance vessel would advance with one turn of propeller if there were no slip. Also applied to angle that propeller blade makes with propeller shaft. It is this pitch which produces propulsion of ship.

Pitch of Rivets – Spacing between rivets measured from centre to centre of the rivets.

Pitch Pine – Resinous European softwood timber of high durability for planking in marine use.

Pitch, pitching: The fore and aft rock of a vessel caused by encounters with waves from head on or astern. Natural tar/mastic used to caulk timber decks.

Pitching – Downward falling of a vessel’s bows as water support leaves them.

Pitch-pole – To be overthrown in a fore-and-aft direction.

Pitometer Log – Submerged log actuated by pressure set up by ship’s advancing through water. Speed is indicated directly; distance run is indirectly obtained by additional mechanism.

Pitting – Visible corrosion causing small pits to form in metal. Pivoting.

Pixel – A picture cell, one of thousands of pinpoints of light that make up the picture on a raster scan radar display.

Plain Sail – Sail with no reef taken in it. Plain Sailing. Colloquial expression meaning everything is going well.

Plain sailing – All is going well. Sometimes less correctly used to mean Plane Sailing, see below.

Plait – Yarns or small line intertwined to make sennit, gaskets or foxes.

Plan – Chart covering a small area on a very large scale. There is no distortion, relative distances and positions being maintained.

Plan Position Indicator – See ‘Cathode Ray Tube’.

Plan Position Indicator (PPI) – the most common type of radar display in which contacts appear in plan form.

Plane – To drive a vessel fast enough to rise up and over the wave of its own displacement so that it skims over the water surface.

Plane Chart – Chart constructed on a supposition that surface of Earth is flat in charted area. Except for small areas at Equator it would be erroneous. Is not used in modern chart construction. Mercator charts were, at one time, called ‘plane charts’.

Plane of Ecliptic – Plane of celestial sphere passing through centres of Earth and Sun.

Plane Sailing – That method of solving certain navigational problems on assumption that Earth’s surface, in the area concerned, is a plane.

Planet – Satellite of Sun that reflects Sun’s light. Excluding minor planets there are eight, Earth not being reckoned. Those revolving inside Earth’s orbit are termed ‘minor planets’, those outside Earth’s orbit being ‘major planets’.

Planetarium – Mechanised model of Solar System, not to scale, used for illustrating movements of planets around Sun, constellations, etc. 2. An auditorium where a representation of the Solar System is displayed on a hemispherical ceiling.

Planetoid – A minor planet, or asteroid. Plank. Technically, length of timber more than 9 inches wide and from U to 4 inches in thickness.

Planing – A boat is said to be planing when it is essentially moving over the top of the water rather than through the water.

Planing Hull – A type of hull shaped to glide easily across the water at high speed.

Plank on Edge Type – Name given to deep and narrow yachts that developed between 1852 and 1876, about. Name is often given to deep and narrow vessels in general.

Plank Sheer – Plank resting on top timbers of ribs or frames.

Planking Clamp – Implement for bending a plank to rib of a wooden vessel, and holding it in place until fastened.

Planks – Wide boards used to make a watertight external covering.

Plankton – Mass of minute animal and vegetable organisms that exists in the sea below the surface and above the bottom. Microscopic organisms drifting in water.

Planter – Tree trunk with its root in bed of a river and its top just below water level. May be a navigational hazard in some rivers of western America.

Plat – Old name for a chart.

Plate – Iron or steel sheet forming part of ship’s deck or hull plating. 2. Iron or steel bar or band—such as ‘Chain Plate’.

Platform – Plated deck, in engine-room, from which the engines are tended and controlled. 2. Name given to ‘Orlop Deck’. 3. Oil industry term for a fixed installation exploiting oil or gas from under the sea.

Platypus – A fresh water, egg-laying mammal; Australia.

Play – Looseness, freedom of movement.

Pledge – Length of oakum used when caulking a seam.

Pleiades – Cluster of seven visible stars in constellation Taurus. Name means, ‘to sail the seas’; this name being given because the ancient Greek navigational season began when Sun and Pleiades rose together.

Pleion – Meteorological term for an area in which meteorological conditions and factors are above normal.

Plimsoll Mark – Marks painted on the outside of a ship (corresponding to the seasons of the year/salinity of water) that are used to limit the loading of a vessel to its stability specifications.

Plot – A diagram for solving navigational or tactical problems. To accurately draw a line on a chart, paper or glass surface that represents a course, bearing or vector of a vessel’s movement i.e.; plotting a vessel’s position or completing a radar plot.

Plotter – A navigational instrument that incorporates its own compass rose and is used for plotting. A feature of a GPS/electronic navigator enabling a chart like display that records a vessel’s movements.

Plotting a Position – One of the most fundamental chart skills is being able to plot a position of known latitude & longitude, or, to determine latitude & longitude of a given position on the chart.

Plough – One of the colloquial names for constellation Ursa Major.

Plough Anchor – See CQR.

Plough Star – Arcturus, in constellation Bootes.

Plug – A tapered cylinder fitting into a hole to seal a compartment. The pattern on which the GRP mould for a hull is laid.

Plug Spanner – A dedicated socket wrench used for fitting spark plugs.

Plume – The feather-shaped echo produced on a radar display by an Echo Box.

Plunging – When ship’s bow dips suddenly due to wave action.

Pluviograph – Self-recording rain gauge.

Ply – To work to windward. 2. To sail regularly between two ports. 3. A strand in cord or rope.

Pneumercator Gauge – Instrument for indicating depth of a liquid, or draught of a ship, by denoting the pressure necessary to balance the gravitational pressure of the liquid—the pressure being indicated by a gauge or a balancing column of mercury. This pressure is read off against a specially-calibrated scale.

Pocky Cloud – Name sometimes given to ‘Mammatus’.

Pod – A small herd of marine animals.

Podger – A short steel bar, pointed at both ends, used as a lever, etc.

Point – Tapered end of a rope with alternate yarns bound round it in alternate succession. Done to prevent fraying of end, and to facilitate reeving through a sheave. 2. Reef Point. 3. Point of compass=11 1/2°.

Point – That point, inside a vessel, on which she turns when under helm. To taper the end of a rope. One of the 32 of 11.25 degree divisions of the compass card.

Point Line – Small rope used for reef points. Usually about inch to 1 3/4 inch in size. Generally referred to by the number of threads, 15 to 21, used in making it.

Point of Definition – An epoch or point from which reckonings are made and measured. Particularly applied to measurements of time. First Point of Aries and mean Sun are points of definition of sidereal time and mean solar time, respectively.

Point of Origin – Accurately determined position used as a point of reference when surveying.

Point of Tangency – Position on a gnomonic chart where the plane to which the various positions were projected was assumed to be touching surface of Earth. At this point there will be no distortion in distance or compass bearings; positions remote from this point will have errors in both distance and bearing, increasing with their distance from the point.

Pointed Sun – Name sometimes given to actual Sun when observing it with a reflecting instrument.

Pointers – Two principal stars of Ursa Major, a line through them pointing to Polaris.

Pointing – Sailing into the wind.

Polacre – Former Mediterranean sailing vessel having three pole masts. Fore and mizen masts were lateen-rigged, mainmast square-rigged.

Polar – Pertaining to poles of a sphere; to extremeties of Earth’s axis; to points in celestial concave immediately above poles of Earth; to points of no magnetic dip on surface of Earth; to points of maximum force in a magnet.

Polar Air – Cold air; not necessarily of polar or even arctic origin.

Polar Angle – Angle, at pole of Equinoctial, between two hour circles or meridians.

Polar Circles – Arctic and Antarctic circles in latitudes 66° 33′ North and South respectively.

Polar Distance – Value, in arc, of that part of hour circle intercepted between elevated pole of celestial sphere and an observed heavenly body.

Polar Front – Line of demarcation that may develop between air from high latitudes and air from low latitudes. A low pressure frontal system born in high latitudes.

Polaris – The Pole Star α Ursae Minoris. R. A. 01 hr. 49 m; Dec. N89°; Mag. 2.1. 2. Missile which can be launched under water and aimed at a target 2500 miles distant.

Polarity – How the current in an electrical circuit passes from the positive to the negative pole of a battery or generator.

Pole – Of Earth, is extremity of its axis of rotation. Of heavens, is a point 90° from every point in circumference of Equinoctial. Of a great circle, is the extremity of a diameter of the sphere passing perpendicularly through centre of the great circle. 2. That part of a mast between truck and upper eyes of rigging. 3. A pole mast. 4. Long spar used for propulsion, in shallow water, by resting end on bottom and applying power to part above water.

Pole Axe – Weapon formerly used when boarding enemy ship. Later called ‘tomahawk’.

Pole Compass – Standard compass shipped on a pole to raise it above iron of ship, and so reduce effects of local attraction.

Pole Mast – Mast made from a single pole, so differentiating it from a made or built mast. A mast constructed of a single piece of timber.

Pole Star Tables – Tables, in Nautical Almanac, by which altitude of Polaris can be used for determining latitude when local sidereal time is known.

Pole Star – Polaris. Navigational star that is nearest to north pole of heavens. Principal star in Ursa Minor.

Policy – In marine insurance is a legal contract of indemnity for a maritime loss. Principal forms are Time, Voyage, Floating and Valued. Issued by underwriters or by corporate bodies.

Policy Proof of Interest – Usually referred to as P. P. I. Term used when person insuring has not declared his interest, but it has been assumed that the policy would not have been taken out unless interest, or contingent interest existed. If no interest exists the insurance is illegal and void in law.

Pollywogs – A first time initiate tried before King Neptune’s crossing the line pantomime court, later renamed a shellback after successfully completing the courts initiation challenges.

Poly Vinyl Chloride (PVC) – A plastic used for canoe and small craft solid moulded constructions. Also, the rubberised fabric is used for cheaper but less durable inflatable dinghies.

Polyethylene – A cheap and widely plastic used for lower quality ropes. It floats, and is available in bright colours.

Polyzoa – Very minute molluscs that exist in colonies.

Pompey – Traditional nickname for Portsmouth.

Ponente – Westerly wind in Mediterranean Sea.

Pontoon – Buoyant construction used for a landing place; for providing a road over water; for raising wrecks; for giving additional buoyancy.

Pontoon Hatch Cover – A heavy hatch cover made as a single piece.

Pool – Enclosed, or nearly enclosed sheet of water. 2. Fluctuating congregation of men from which can be drawn hands required for manning ships, and to which can be added men available for manning.

Poop – The after (raised) deck area of a vessel.

Pooped – A sea that breaks onto a vessel from astern.

Pooping – Said of a vessel, or of the sea, when following seas sweep inboard from astem.

Poor Jack, Poor John – Salt fish, particularly salt cod, when issued as rations.

Popham’s Code – System of signals, by flags, devised by Captain Sir H. Popham, R. N., in 1800, for communication between ships of Royal Navy. Was used in making Nelson’s memorable signal at Trafalgar.

Poppets – Shaped pieces of wood that close the cut away parts of wash strake through which oars project when rowing. 2. Shores on bilgeway of launching slip, and forming part of cradle.

Popple – A short, confused sea.

Porcupine – Nickname for a wire rope when broken wires stand out from it.

Port – Harbour or haven in which shipping can lie in safety. Legally: a harbour with facilities for ships to load, unload or obtain supplies, and which has been appointed for travellers to enter or to leave the country. 2. In ship construction, an opening in ship’s side to allow light or air to enter; for cargo, or baggage, to be taken in or discharged; for a gun to protrude; for water on deck to flow overboard, and other similar purposes. 3. In engineering, is an opening in a valve, cock, or cylinder to allow passage of steam, liquid or gases. 4. As a direction, is equivalent to ‘left hand’ when facing forward.

Port Admiral – Admiral in charge of a Naval port.

Port Authority – Corporate body, or individual, responsible for the administration of a port area and for the carrying out of statutory duties.

Port Bar – Shoal at entrance of a port. Boom protection at entrance of port during hostilities. 2. Bar by which the fitting that closes a port in ship’s side is made watertight and secure.

Port Charges – Port dues. 2. Expenditure consequent on a vessel being in port.

Port Clearance – Document certifying that vessel has liberty to leave a port. Issued by appropriate authorities for the port.

Port Dues – Established charges, made by a port authority, payable by vessels entering or using the port.

Port Flange – Small guttering above a port hole or scuttle to deflect water running down ship’s side. Also called ‘Rigol’ or ‘Eyebrow’.

Port Hole – Small aperture, usually circular, in ship’s side. Windows in the side of a vessel. Called scuttles in the navy. Used for lighting, ventilating and other purposes.

Port Lanyard – Small length of rope or chain by which a port may be opened or closed.

Port Lids – The covers of gun ports.

Port Marking – Distinctive mark put on cargo for one particular port when carrying cargoes for more than one port.

Port of Call – Port where a shipis heading into for loading, discharging, or other purposes.

Port of Refuge – Place or harbour, other than loading port or intended destination, to which a vessel proceeds to avoid an imminent peril.

Port of Registry – A vessel’s home port in the country under whose flag it is registered.

Port Policy – Contract of marine insurance covering risks that may arise while vessel is laid up in port.

Port Riggle, Rigol – Rigol above a scuttle or port in an exposed position.

Port Sail – Old sail, used as a ‘save-all’, between a lighter and a ship that is loading or discharging cargo.

Port Sanitary Authority – Body appointed to carry out statutory duties of a port authority in regard to all matters concerning health and prevention of disease in connection with shipping. Responsible for inspection of ships, and deratisation.

Port Sash – Window fitted into upper half of a square port.

Port Side – The left hand side of a ship looking forward.

Port Sill – One of the four short timbers lining a square port.

Port Speed – Rate of loading or discharging at a port when considered in conjunction with the working hours of the port.

Port Tack – When the wind comes from the port side, and the fore and aft sails are displaced to the right hand of the vessels centreline.

Portage – Wages of seaman earned in a complete voyage. 2. Short stretch of land that interrupts a line of water communication between two places — a boat has to be carried or transported across it.

Portage Bill – Document showing earnings of each member of crew, during a complete voyage, together with all rightful deductions to be made. These deductions include such moneys as allotments, advances of pay, etc.

Portfire – Casing containing an inflammable composition that burns slowly in all states of weather. Used for early distress rockets etc.

Portlast – Gunwale, or upper edge of bulwarks, of a ship.

Portoise – ‘Portlast.’

Portolan Charts – Hand-drawn charts of 14th century.

Portolani – Italian sailing directions of 13th and 14th centuries.

Portuguese Man of War – Jellyfish with large oblong air-bag and pendulous tentacles. Stings when touched.

Portuguese Sennit – Alternative name for ‘Boatswain’s Plait’.

Poseidon – Ancient Greek God of the sea.

Position Circle – ‘Circle of Position.’

Position Fixing Instruments & Systems – Any combination of these methods of determining a line of position permits fixing the position of a craft. Fixes may be arrived at by cross bearings, by a bearing and distance of the same object, by a bearing and a sounding taken simultaneously, by horizontal sextant angles, and by two bearings of a single object taken at different time intervals but adjusted for time lapse when plotted known as a running fix.

Position Line – ‘Line of Position.’ A line drawn on a chart representing a direction from an object derived from a compass bearing, transit or other observation.

Positive Pressure Respirator ; A respirator in which the pressure inside the respiratory inlet covering exceeds the ambient air pressure outside the respirator.

Positive Slip – Difference between theoretical advance of ship, by propeller action, and the actual advance made when it is less than theoretical advance. Due to propeller working in a yielding medium. (‘Slip.’)

Possibility Area – (1) The smallest area containing all possible survivor or search object locations. (2) For a scenario, the possibility area is the smallest area containing all possible survivor or search object locations that are consistent with the facts and assumptions used to form the scenario.

Post Captain – Former rank in R. N. Denoted a Captain who had been in command of H. M. ship for three years.

Post Meridian – ‘Post Meridiem.’

Post Meridiem – Latin for ‘After noon’.

Post Ship – Former name for a first-class warship. Related Article: Types of Warship in a Naval Fleet.

Pouch – Name formerly given to a ‘grain feeder’ or a space enclosed by shifting boards.

Pound, Pounding – When a vessel rises over a wave and falls back to strike hard on her forefoot with jarring force.

Pounding – The heavy falling of a ship into the sea, or on the ground, after having been lifted by wave action.

Pouring oil on troubled waters – Heavy-weather practice of pouring oil on the sea to form a surface film that minimises the seas from breaking. To smooth out some difficulty.

Powder Magazine – Space in which gunpowder charges are stowed.

Powder Room – Space in which bulk gunpowder is stowed.

Powderhorn Sheer – A rise in the sheer towards the bow (at the shoulder) and a smaller rise at the stern to promote dryness.

Power-driven Vessel – Means any vessel propelled by machinery.

Prahu – Malayan craft propelled by oars and sails. About 50 ft. long. Also, double-ended boat of Ladrone Islands. About 30 ft. long and fitted with outrigger. Steered with paddle.

Pram – Dinghy built with a small tramson at the bow as well as at the stern.

Pratique – Licence of a ship to trade having been declared in good health by medical and sanitary authorities.

Prayer Book – Seaman’s nickname for a small holystone.

Precession – Movement of axis of a free gyro when subjected to an angular force that is not coincident with plane of rotation. It results in direction and plane of spin taking up a position so that each particle in gyro takes the shortest course to the new points arising from the angular movement of axis.

Precession of Earth’s Axis – Slow, circular movement of Earth’s poles around axis of Ecliptic at an angular distance of 23° 27′. Period of the movement is nearly 26, 000 years. Caused by gravitational pull of Sun and Moon and Earth’s equatorial bulge.

Precession of Equinoxes – Gradual backward movement of First •Points of Aries and Libra along the Ecliptic so that their celestial longitudes are continuously decreasing.

Precipitation – All of the forms of water particles, liquid or solid that fall from a cloud and reach the ground; drizzle, rain, hail, snow, sleet.

Pre-formed Wire – Wire with strands made to shape without twisting.

Premium – Money paid for insurance against a marine risk.

Press Gang – Naval ratings, under an officer, who went ashore and impressed men into naval service.

Press of Canvas – All sail set and all sails drawing.

Pressure Demand Respirator – A positive pressure atmosphere-supplying respirator that admits breathing air to the face piece when the positive pressure is reduced inside the face piece by inhalation.

Pressure Gradient – Rate of change of barometric pressure across isobars in a synoptic chart. The closer the isobars are together, the higher the pressure gradient is and the stronger the winds will be.

Presumed Total Loss – Said of a vessel when she has not been sighted or heard of for a considerable time but there is no evidence of her having sunk or being destroyed.

Preventer – Term applied to duplicated rigging. In some cases it seems to be used with its original—and literal—meaning of ‘coming before’.  A line or spar used to limit the free movement a sail, cargo hook or boom.

Preventer Backstay – Topmast backstay that could be slacked off when on lee side and vessel close-hauled.

Preventer Bolts – Through bolts along lower edge of preventer plate. Used for backing up chain-bolts passing through upper edge of plate.

Preventer Fid – Iron bolt sometimes kept along, and secured to, eyes of topmast rigging. Directly heel of mast was clear of mast hole in trestle trees, when hoisting, fid was passed through hole in mast so that mast would not fall to deck if mast rope parted.

Preventer Main Braces – Main yard braces that led forward. Were additional to braces leading aft.

Preventer Plates – Iron plates running downwards, on sides of wooden vessels, from chains to strakes below. Purpose was to spread strain of shrouds and prevent seams of side opening.

Prick – To mark off ship’s position on a chart. To draw a course on a chart. 2. To put an additional seam in middle of cloth of a sail.

Pricker – Small, thin marline spike used for stabbing holes in canvas and when splicing small rope.

Pricking Note – Customs document authorising the shipment of stated goods.

Pricking off the Ship – Marking ship’s position on chart—generally at noon.

Pride of the Morning – Mist at sunrise: usually indicating a fine and sunny day.

Primage – Money paid by shipper to the Master of a ship for diligence in care of cargo. Not now paid to Master, but added to freight. Amount was usually about 10% of freight.

Primage and Average Accustomed – Words inserted in a Bill of Lading when an additional payment is due, at customary rate, on right delivery of cargo.

Primary Circle – That great circle that is a plane of reference for all great circles passing through its poles. Primary circle of Earth is Equator.

Primary Fixing Method – The science of navigation is divided into Four Principal Techniques: (1) so-called Dead Reckoning which is derived from the phrase deduced reckoning, and estimates the approximate position of a craft solely from its course and speed; (2) Piloting, which involves guiding the craft by frequent reference to geographical landmarks and navigational aids and by use of soundings; (3) Celestial Navigation, which uses the observation of celestial bodies to determine position on the surface of the earth; (4) Electronic Navigation, the most important and advanced system of navigation today, using radio and electronic equipment. Related Article: Types of Marine Navigation.

Primary Planet – Name sometimes given to those planets revolving around Sun, thus distinguishing them from lesser bodies revolving around a planet.

Primary Swell – The swell with the greatest height from trough to crest.

Primary Tide – That part of a tidal undulation that is the direct response to a tide generating force. Term is used when comparing it with a composite tide.

Prime Entry – Statement made to Customs authorities, by Master of an arrived ship, declaring the nature and approximate quantity of cargo brought in. Is a pre-requisite for inward clearance.

Prime Meridian – That meridian from which longitude is reckoned. By common consent this is now the meridian of Greenwich.

Prime Vertical – Great circle of celestial sphere, and secondary to horizon, passing through east and west points of horizon.

Priming and Topping – Preparation of a boiler furnace before lighting fire. Priming consists of laying small coal over fire-bars. Topping is the laying of a transverse wall of coal a little distance inside furnace. Kindling wood, or fire from another furnace, is laid against topping to ignite it.

Priming Valve – Spring-loaded valve, on top of cylinder, that allows any condensed steam to escape as piston comes upward.

Prismatic Coefficient – Immersed volume of a vessel expressed as a fraction of a block whose length is that of the vessel and the shape of which is that of the immersed midship section of the vessel.

Prismatic Compass – Compass fitted with a reflecting prism and a sighting vane. Used for observing azimuths.

Prismatic Telescope – Telescope having reflecting prisms to enlarge an observed object. Periscope is a well-known example.

Private Ship – Naval term for any warship that is not a flag ship.

Privateer – Ship, other than a warship, fitted out by persons to whom letters of marque had been given. Name was also given to person commanding such a ship. To privateer is to attack enemy shipping under letter of marque.

Priveleged Vessel – A vessel which, according to the applicable Navigation Rule, has right-of-way (this term has been superseded by the term “stand-on”).

Prize – Vessel captured in war and granted to capturers by sovereign.

Prize Court – Wartime court set up to adjudicate on naval prizes taken.

Prize List – Names, ranks and ratings of personnel in a captured ship.

Prize Master – Officer, from capturing ship, who takes charge of a captured ship.

Prize Money – Share of value of captured merchant ships, paid to crews of H. M. ships. Originally paid to personnel of capturing ship, but in war of 1914-18 was shared amongst all personnel. In war of 1939-45 was shared amongst R. N. and R. A. F. Now discontinued.

Pro Forma Policy – Temporary and unsigned policy issued to an insurer pending the preparation and signing of the actual policy.

Proa – Canoe of Ladrone Islands. One side is curved, the other straight, outrigger being fitted on straight side. Has lateen sail and can be sailed either way. Usually about 30 ft. long and 3 ft. beam. The forward part of the vessel.

Probability Area – The area in which a missing craft and/or survivors are most likely to be found taking into account possible errors in the navigation of the missing craft and of the search craft.

Probability of Detection (POD) – of a search object being detected, assuming it was in the areas that were searched. POD is a function of coverage factor, sensor, search conditions and the accuracy with which the search facility navigates its assigned search pattern. Measures sensor effectiveness under the prevailing search conditions.

Procuration – The acting of one person on behalf of another. 2. A document authorising one person to act on behalf of another.

Procyon – Star α Canis Minoris. S. H. A. 246°; Dec. N05°; Mag. 0.5. Diameter is twice that of Sun, candlepower being 5 times greater. Distant 10 light years; temperature 6500°A. Name is Greek for ‘Before the Dog’, on account of it rising before Sirius.

Product Carrier – A smaller tanker used to carry refined oil products. Four different grades of oil may be handled simultaneously. Related Article: How to Identify Oil Tanker Sizes- Handymax, Panamax, Aframax, Supertankers.

Profile Draughts – Two sheer plans on principle of cargo plans. One gives layout of ship; the other giving layout of fittings in ship.

Profile Plan – Elevation of the longitudinal shape of a hull; sheer plan.

Progressive Wave – Elevation of water, with its accompanying depression, that moves laterally along surface of sea. Considered in tidal investigations.

Projections – Attempts to delineate some part of curved surface of Earth on the flat surface of a map or chart. It is impossible to do this with accuracy. In the projections used by seamen the distortions are either negligible in practice or are of a known nature and value and can, therefore, be allowed for. The different projections are treated under their separate names.

Prolate Spheroid – Spheroid generated by semi-rotation of an ellipse around its major axis. Sometimes applied to a spheroid that rotates on its major axis.

Prolongation Clause – Inserted in a charter party to give charterers option of continuing a charter beyond a given date. States the conditions under which this can be done.

Prolonged Blast – Blast, of 4 to 6 seconds duration, on a whistle, foghorn, or siren.

Promenade Deck – One of the decks of a passenger steamer. Usually more or less  open and free from obstructions.

Promissory Note – Written and stamped undertaking to pay a specified sum of money on or before a specified date.

Proof Load. – Excessive load put on an item under test. May vary between 10% and 100% more than the load that the item is intended to take.

Proof Strain – Excessive strain put on an item under test. Always exceeds strain that the item is intended to take.

Proof Stress – Value used to indicate strength of metal when it is difficult to determine yield point. Metal is stretched and its elongation under the stated stress is expressed as a percentage, the value of the stress being stated.

Proof Timber – Vertical straight line, representing a timber, drawn on a sheer draught for checking fairness of ship’s form.

Prop Rider – A hydroplane design in which the propeller serves as point of support when planing.

Propeller – Instrument by which a vessel is propelled. Attached to after end of a shaft that is connected to engine. Usually has three or four blades, each being part of a screw thread, and is keyed and secured to after end of tailshaft.

Propeller Post – That part of stem framing that carries after end of stern tube, and supports end of tail shaft.

Propeller Shaft – The shaft connecting the propeller to the gear box.

Proper Motion – The actual movement of a heavenly body as distinguished from a parallactic change in its position due to Earth’s movement in space. Name is given, also, to Sun’s apparent movement in Ecliptic, to distinguish it from his apparent diurnal motion. 2. The movement on a true-motion radar display of the echo of another ship. It shows her course and speed. (‘Course Steered and Speed.’)

Proper Pilotage – That branch of navigation dealing with the conducting of a ship by methods involving astronomical observations and calculations. Now termed ‘Navigation’ or ‘Astronomical Navigation’. In Elizabethan times it meant ocean navigation.

Proper Return Port – Port to which a seaman can claim to be returned on completion of his service to a ship.

Propogation – Movement of crest of a progressive wave.

Proportional Lengths – Relative dimensions of a ship and appropriate lengths of masts and spars. These used to be tabulated thus:— Length of Ship= Breadth x 7. Main Yard=2.3 Breadth. Depth of Hold=Lengthx0.09. Lower Topsail Yard=1.85 Breadth. Mainmast=Breadthx2.25. Spanker Gaff= Breadth. Foremast=Breadthx2.09. Bowsprit=0.7 Breadth. Mizen Mast = Breadth x 2.

Proportional log – of 2 hours would be log. of 10, 800 minus log. of 3600. Now quite obsolete for this purpose.

Proportional Logarithms – Used when ‘Clearing a Lunar Distance’. Was the logarithm of 10, 800 (the number of seconds in 3 hours) diminished by the number of seconds by which a quantity dealt with was less than 3 hours.

Propulsion – The driving forward of a vessel.

Protection and Indemnity Association – Association of shipowners who combine to indemnify any of their members against third party claims and against risks not normally covered by marine insurance.

Protest – Statement under oath, made before a notary public, concerning an actual or anticipated loss, damage or hindrance in the carrying out of a marine adventure.

Proved – Said of anchors and chain cables when they have been tested and found to be of required quality and strength.

Proving Establishment – Establishment where anchors and chain cables are tested and proved.

Prow – Old name for stem of a vessel, or for the bows. 2. Alternative name for ‘Proa’. The part of the ship’s bow above the water.

Proxima Centauri – Name given to α Centauri on account of it being the nearest star to Earth.

Proximate Cause – Nearest or most immediate cause of a maritime loss. Used in marine insurance when a loss is due to a sequence of events or a combination of circumstances.

Pruning – Of tide, is a decrease in time interval between successive high waters. Roughly speaking, it occurs as tides decrease from spring to neap. 2. Of a boiler, is the projection of minute particles of water into the steam; generally due to impurities in feed water, or to violent motion of ship. 3. Of a pump, is the insertion of water to expel air. 4. In painting, is the first coat applied to a bare surface.

Psi – Pounds per square inch.

Psychrometer – A hygrometer, but sometimes limited to those hygrometers in which air-flow past wet bulb is accelerated by mechanism.

Pteropod Ooze – Ooze containing small conical shells. Found in various areas at depths between 400 and, 1500 fathoms.

Puddening – Rope strands when used to make a fixed fender or chafing gear. Strands are usually woven, but not always so.

Pudding Chain – Short link chain especially made for reeving through a block. Used for halyards and sheets before wire rope was introduced.

Pudding Fender – Cylindrical canvas bag containing cork or coir and covered with leather or grafted small stuff.

Pulley – Block with sheave to change direction of rope or to give mechanical advantages—in latter case is usually called a ‘tackle’.

Pulling (an Oar) – Propelling a boat by facing aft and pulling on an oar, or oars.

Pulling Boat – Any boat propelled by the pulling of oars.

Pulpit – A guard rail structure at the bow of a vessel.

Pulse – Very short (usually less than one-millionth of 1 second) radio signals transmitted in rapid succession by a radar transmitter.

Pulse Length – The duration of transmission of radio waves or microwaves.

Pulse repetition frequency (PRF) – of a radar pulse, the number of pulses transmitted per second.

Pump Box – Casing covering top of a pump. 2. Leather piston fitted with a nonreturn valve.

Pump Brake – Handle by which a pump is worked.

Pump Hook – Hook, with long handle, for lifting a leather pump box.

Pump Leather – Stout leather from which pump boxes were formerly made.

Pump Spear – Rod to which upper pump-box was attached.

Pump Well – Shaped space into which water flows, and from which it is pumped; pump suctions leading to it.

Pumping – Of barometer: fluctuations in height of mercury column due to violent movement of ship, or of wind effect at cistern.

Punt – Small craft propelled by pushing on a pole whose lower end rests on the bottom of the waterway. 2. To propel a boat by resting end of a pole on bottom of waterway. 3. Copper punt.

Puoy – Spiked pole used for propelling a barge or boat by resting its outboard end on an unyielding object.

Purchase – Mechanical advantage gained by leverage, tackle or positioning. 2. Apparatus by which mechanical advantage is gained.

Purchase Blocks – Sheaved blocks used in forming a purchase.

Purchase Fall – Rope rove through blocks to obtain mechanical advantage.

Purple Light – Rather bright patch of sky sometimes observable about 25° above point at which Sun set Maximum brightness occurs when Sun is 4° below horizon.

Purse – Bag-shaped fishing-net, the mouth of which can be drawn together and closed.

Purser – Usually pronounced ‘pusser’. Officer responsible, under Captain, for ship’s disbursements, money transactions and stores. In R. N. he has been displaced by accountant officers. In 17th century he was responsible to owners for all cargo and freight transactions.

Purser’s Dip – A candle.

Purser’s Dirk – Nickname for a midshipman’s dirk, and for uniform pattern knife carried by seaman in R. N.

Purser’s Eighths – Deductions from certain stores that was, formerly, retained by a purser in R. N. as an agreed payment for his services. Discontinued in 1852.

Purser’s Grin – Hypocritical smile, or sneer.

Purser’s Knife – Seaman’s clasp-knife, of uniform pattern, in R. N.

Purser’s Pound – Sixteen ounces less 1/8; 14 ounces.

Push Pit – A guard rail structure at the stern of a vessel.

Push Rod – A steel rod that when displaced by the camshaft moves the rocker arm of an overhead valve engine.

Pusher – After mast in a six-masted sailing vessel.

Pushpit – A guard-rail round the stem of a yacht.

Pusser’s Pound – The 18 Century Royal Navy purser was allowed to profit by 2 ounces on each pound (16 ounce) of goods he sold to the crew, hence the pursers short pound of 14 ounces.

Put – To change direction of a vessel: e. g. to put about.

Put To Sea – To depart from a port.

Puttock – Corrupted form of ‘Futtock’.

Putty – A mastic type filler made from chalk or lime mixed with linseed oil.

Pyranometer – Instrument for measuring either nocturnal radiation or sky radiation.

Pyrgeomete –. Instrument for measuring nocturnal radiation.

Pyrheliomete –. Instrument for measuring rate at which heat falls on earth’s surface.

Pyrometer – Instrument for measuring very high temperatures. Usually based on increased electrical resistance of platinum wire when heated.

Pythagoras’ Theorem – The area of a square on hypotenuse of a right-angled triangle equals sum of squares on other two sides. An important trigonometrical corollary from this is that Sin Cos l. 2 2 Θ + Θ =

Pyxis Nautica – Former name for a mariner’s compass in a box.

Gibi

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