Characteristic. Of a logarithm, is the whole number of the Log, as distinguished from its
mantissa. 2. Of a navigational light, is its colour, phase and period.
Charges Clause. Inserted in Charter Party to denote who shall pay harbour and dock dues,
wharfage, pilotage, towage, etc.
Charles's Law. States that volume of a gas, at constant pressure and at temperature 0°C
increases by 1/273rd for each degree rise in temperature.
Charles's Wain. 'Churl's wain,' or 'waggon'. Old name for 'Ursa Major'. Charley Moore. The embodiment of fair dealing. (R.N.)
Charley Noble. R.N. nickname for a galley funnel.
Chart. Representation of part of ocean or sea for use in navigation. Gives depth of water,
nature of bottom, configuration and characteristics of coast, with positions and brief particulars of navigational aids. 2. Diagram showing certain facts in graphical or tabular form. 3.* Old name for mariner's compass.
Chart Abbreviations. Standardised abbreviations used in charts. The more important are
generally shown under chart title, but all those used in British Admiralty charts are given on a special chart.
Chart Border. Graduated lines, at border of chart, for determining latitude and longitude of
a position, and for measuring distances.
Chart Compass. Compass rose engraved on chart, to determine courses and bearings.
Usually has an outer graduation 0°-360°, and inner graduation in quadrantal form. Inner compass gives variation, for a given epoch, and the secular change.
Chart Datum. Sea level used in connection with soundings on a chart. In British charts, is a
level below which the tide very rarely falls.
Chart Distortion. Differentiated into distortion in and distortion of charts. Distortion in a
chart is an unavoidable extension of charted area due to impossibility of accurately
reproducing a spherical surface on a plane surface. It is adjusted by extending the units of measurement, latitude or longitude, to correspond with the extension of the area. Distortion of a chart is a possible stretching or contraction that may occur after printing, and so cause a slight relative displacement of a charted positions. In modern charts this distortion is rarely enough to affect navigation, but if the chart be large it may affect very precise surveying.
Charterer. One who enters into a contract with a shipowner for the hire of a vessel, or for
the carriage of goods by sea.
Charter Party. Document by which a shipowner leases his ship to some person or persons,
or by which he agrees to carry goods or perform other services. It states the conditions, terms and exceptions that are to prevail in the contract.
Chart Plate. Plate, usually of zinc or copper, on which a chart is engraved for printing. The
exact size of this plate is given, in inches, in border of chart. This allows for checking the chart for distortion.
Charybdis 79 Chevils
Charybdis. Name of one of the whirlpools, or garofali, in Straits of Messina.
Chasse Marees. Bluff-bowed French luggers formerly used for fishing, and in short voyage
trades. Had up to three masts and often carried topsails.
Chatham Chest. Fund for support of disabled and superannuated seamen of R.N. Founded
in reign of Queen Elizabeth, on a voluntary basis which, later, became compulsory. Abolished during reign of William IV.
Chebacco Boat.* Sailing craft formerly used in Newfoundland fisheries. Had high, narrow
stern. Named after a small river in Massachusetts.
Check. To ease a rope a little, and then belay it.
Checking. Slacking a rope smartly, carefully and in small amounts.
Check Stopper. Length of small chain with one end made fast to a ring bolt, or other
annular opening, then around a wire and back through the ring bolt. By hauling on free end of chain the speed of a moving wire can be checked and regulated.
Cheek Block. Sheave on side of a spar, etc., and having a half shell on outer side.
Cheeks. Brackets below head of mast and at sides of it. Support crosstrees and mast above.
2. Knee pieces either side of stem. 3. Sides of a wooden (pulley) block. 4. Old name for a Royal Marine.
'Cheerily.' Injunction to perform an action smartly and with a will.
Cheese Cutter. Form of drop keel for small craft. Has a projecting upper part that is
supported in housing when keel is down. 2. A peak cap.
Cheesing down. Coiling a rope ornamentally with each flake flat, or almost flat, on deck;
usually in a circular or figure-of-eight pattern.
Chequered. Said of a flag or pendant made up of small squares of two different colours; and
of a buoy or beacon painted in squares of two different colours.
Chernikeef Log. Submerged log that projects through bottom of ship. Carries an 'impeller'
that turns as vessel moves through the water. Directly records distance run and, with electrical attachment, can indicate speed.
Cherub Log. Towed log consisting of a towed rotator, non-kinkable log line and an inboard
registering unit. Measures distance directly, and can be used for speeds up to 12 knots.
Chess Tree. Oak block secured to ship's side abaft fore chains. Used for boarding main
tack, or as lead for fore sheet.
Chest Rope. Long boat rope led from forward to a gangway into ship.
Chetwynd Compass. Liquid type compass for use in quick-turning craft. Drag of liquid on
rim of card was reduced by making card much smaller than containing bowl.
Chief Buffer 80 Chromatic Aberration
Chief Buffer. Nickname for a chief boatswain's mate in R.N. He is senior chief petty officer
of upper deck, and so acts as buffer between the hands and the Commander.
Child Fender. Roller fender for wharf or quay. Consists of a central shaft, free to rotate,
around which are large diameter rubber tyres filled with cork.
Chiliad. 18th -century name for logarithmic tables. Means '1000'.
Chime. Projection of staves beyond head of a cask, barrel, etc. Chime Hoop. Hoop that protects chime of a cask, barrel, etc.
Chimes. Intersection of the lines forming sides and bottom of a flat-bottomed boat. 'Chine.' Chinckle. Small bight in a rope or line. Often called 'half crown'.
Chine. Former name for chime of a cask. 2. Gap in landward side of a cliff. 3.* That part of
a deck waterway that is left above deck level, so that spirketting may be caulked. 4. 'Chimes.'
Chinese Windlass. Machine, by which purchase is gained by heaving one part of a rope, on
a drum, and veering the other part on a drum of smaller diameter—a block being in bight of rope between the two drums. This principle is adopted in the 'differential' block.
Chinse. To fill a seam or crack by inserting oakum.
Chinsing Iron. Steel or wrought iron tool used for inserting oakum in a seam in planking,
etc. Has a curved lower edge scored with a groove. Upper extension of handle has a wide, circular, convex head for applying power with a mallet.
Chip Log. Quadrantal piece of flat wood, weighted on curved rim, attached to log line for
finding speed of a vessel. Often called 'ship' log, or log 'ship'.
Chippy Chap. Nickname for ship's carpenter, or one of his crew. Chips. Nickname for a ship's carpenter.
Chocks. Shaped pieces of wood on which various items rest and are secured. Of capstan, are
wooden blocks, at top and bottom of drum, that house wooden whelps.
Chock a Block. Said of a purchase when two blocks are close together, and further hauling
is impossible. Also called 'Two blocks'.
Choke a Luff. To prevent a tackle walking back by passing a bight of the fall between a
sheave and the rope rove through it, and on that side of sheave where rope would go into block if walking back.
Cholera. Infectious disease of Eastern origin. Marked by diarrhoea, cramp, vomiting and
drying of tissues.
Chop Mark. Merchant's mark on goods. Indicates grade and other particulars.
Chops of the Channel. Sea area immediately to westward of English Channel. First known
use of this name was in 1748.
Chromatic Aberration. Deviation of light rays after passing through curved lens. Results in
coloured fringes around observed objects, caused by unequal refraction of lenses breaking up light into its constituent colours.