Above Board - To take aboard was to take useful things above deck, ready to use. All above board referred to the fact that the boards of planking which make up the decks are in plain view to everyone.

As The Crow Flies - British coastal vessels customarily carried a cage of crows. Crows detest large expanses of water and head, as straight as a crow flies, towards the nearest land if released at sea - very useful if you were unsure of the nearest land when sailing in foggy waters before the days of radar. The lookout perch on sailing vessels thus became known as the crow's nest.

Between The Devil And The Deep Blue Sea - In traditional wooden ships, sailors had to caulk or pay the seams between planks with hot tar to keep their ship from leaking to the bilges. The devil seam was topmost in the hull, next to the scuppers (waterways or gutters) at the edge of the deck. It was thus the longest seam on the vessel and, not being flush as with other hull seams, the seam that was most prone to spring a leak. A sailor knocked down by a wave would find himself scuppered and lying between the devil and the deep blue sea

Canvas - (from the Greek Kannabis) was made from hemp (as is cannabis) but modern sails, although still called canvas, are made from terylene, polyester, dacron, kevlar and other man made fibers.

Chewing The Fat - Before refrigeration, food was preserved in brine within wooden casks. In time, the salt-hardened fat on the meat, became stuck to the sides of the barrel. But the cook would not waste this and could often be seen scraping the barrel whilst the crew impatiently waited and chewed the fat. The hard fat was perfect for greasing masts and preserving leather fittings, so to prevent the crew from using it all, the cook would secrete it in his 'slush fund', selling the excess ashore to candle makers and fish and chip shops.

Clean Slate - It was the custom in sailing ships to record courses, distances and tacks on a log slate. The new watch would always use a clean slate if things were going fine, disregarding what had gone before and starting anew.

Crows Nest - See 'As the Crow Flies'

Fly By Night - When sailing downwind at night a large fly-by-night would be used to do the job of several smaller, more intricate sails. It required less attention but could only be used downwind and therefore was seen infrequently by sailors.

Footloose - The bottom of a sail is called the foot. It is usually tied to a boom, but when it is footloose (or loose-footed) it often dances freely in the wind, as if with a mind of its own.

Freeze The Balls Off A Brass Monkey - Between the guns, pyramids of cannon balls stood upon lipped edged trays called monkeys. In some ships these monkeys were made of brass (for ceremonial reasons). In cold weather, the different coefficient of expansion meant that the brass trays would contract faster than the iron cannon balls. Sometimes it was cold enough to freeze the balls off a brass monkey.

Let The Cat Out Of The Bag - Sailors would sometimes bottle up their rum ration for a time when they considered it might be more suitable for a wild session, but the sailor found drunk on duty would be required to fashion a cat o' nine tails or make a rod for his own back which would then be kept in a leather sack. When sailors let the cat out of the bag, bad fortune befell them, usually on punishment day, which aboard ship was Blue Monday.

Limey - In 1795 the issue of lime juice aboard British naval ships was implemented to prevent scurvy amongst sailors. British naval ships are still required to carry lime juice and American sailors persist in calling British sailors limeys.

Luff - Loef is a Dutch word meaning windward. A-luff (or aloof) describes a vessel which may be sailing along a lee shore, bearing up, pinching her head high into wind to prevent her being set ashore. To luff up is to point the sail further in to wind - to pinch in fact

Nipper - The anchor warp in large sailing ships (cables) were too large to bend around a capstan. Smaller lines were used to heave the cables and these were nipped to the cable by small boys, who became known as nippers.

Port - (larboard) or left side, is an abbreviation of porta il timone (carry the helm)

Posh - In the days when the only way to India was by sea, it was customary for wealthy passengers to book cabins on the cool side of the ship - port out, starboard home, hence the acronym posh.

Rubbing Salt in a Wound - Roman sailors were paid a quantity of salt as part of their salarium (from the Latin sal meaning salt). These sailors did not take kindly to losing part of their salary when having to rub salt into wounds after battles.

Shake A Leg - In Portsmouth, women would come aboard naval vessels to aid ship morale. Shore leave was often forbidden for fear that pressed men (landlubbers who were forced into service by press gangs) would desert. Each morning the petty officer would shout for the occupants of hammocks to shake a leg. If the leg was smooth and shapely, the occupant was allowed to sleep in; if the leg was hairy, the officer turned out the hammock for the sailor to swab the deck

Ship Shape (And Bristol Fashion) - The Port Of Bristol was once famous for importing tobacco, sherry, chocolate and slaves. Slave ships smelled and could bring disease. They were not allowed into port until they were cleaned and made tidy (tides are predictable and ordered). Before entering Bristol, slave ships were rigorously inspected so as to be ship shape and Bristol fashion

Son of A Gun - The gun decks offered convenient spaces for childbirth. Children born on the gun decks could never be certain of their father and were entered in the Deck Log as a son of a gun

Square Meal - If sailors were lucky, they could go below to eat a square meal off the square wooden platters that cook stowed in a rack.

Starboard - Steor is the Anglo-Saxon word for star and bord is a rudder or oar, always fitted on the right side of ships as most Saxon and Viking sailors were right handed. The steering bord side (starboard) is the right side of a ship (looking forwards).

The Cut of His Jib - The Bay of Biscay is notoriously stormy. French and Spanish ships which frequented this water, had their foresails cut thin, so that they should not be blown off the wind when pointing. Upon seeing an unexpected three decker crest the horizon, a smaller British frigate captain might not like the cut of his jib and decide to cut and run, the crew cutting the lashings on all sails to run off before the wind at speed.

Three Sheets To The Wind - On a Bermuda rigged (two sailed) vessel there are three sheets (two for the jib/foresail and one for the main sail). If a yacht is three sheets to the wind then the sails are not drawing wind and the boat will not make headway (forward progress) but will drift downwind. Sheets might have been let fly, to thrash out of control beneath the flogging sails. On land, windmills have four sails. The sails are covered with sheets of fabric. The windmill turns at full speed with four 'sheets' (sails) exposed to the wind but will work more efficiently in brisk winds with only two 'sheets'. If you put up three sheets to the wind the windmill will be unstable, wobbling on its axis like a drunken sailor. At sea, sheets should never be confused with sails.

Sailing Terms - Humorous

Anchor: Any of a number of heavy, hook-shaped devices that is dropped over the side of the boat on the end of a length of rope and/or chain, and which is designed to hold a vessel securely in place until (a) the wind exceeds two knots, (b) the owner and crew depart, or (c) 3:00 AM.

Bar: Long, low-lying navigational hazard, usually awash, found at river mouths and harbor entrances, where it is composed of sand or mud, and ashore, where it is made of mahogany or some other dark wood. Sailors can be found in large numbers around both.

Beam Sea - A situation in which waves strike a boat from the side, causing it to roll unpleasantly. This is one of the four directions from which wave action tends to produce extreme physical discomfort. The other three are bow sea (waves striking from the front), following sea (waves striking from the rear), and quarter sea (waves striking from any other direction).

Berth: Any horizontal surface whose total area does not exceed one half of the surface area of an average man at rest, onto which at least one liter of some liquid seeps during any 12-hour period and above which there are not less than 10 pounds of improperly secured objects.

Boom: Laterally-mounted pole to which a sail is fastened. Often used during jibing to shift crew members to a fixed, horizontal position. Called boom for the sound that's made when it hits crew in the head on its way across the boat. For slow crew, it's called `boom, boom.'

Bulkhead - Discomfort suffered by sailors who drink too much.

Burdened Vessel - The boat, which, in a collision situation, did not have the right-of-way. See Privileged Vessel.

Calm - Sea condition characterized by the simultaneous disappearance of the wind and the last cold beverage. 

Captain - See Figurehead.

Canvas - An abrasive sailcloth used to remove excess skin from knuckles.

Caulk - Any one of a number of substances introduced into the spaces between planks in the hull and decking of a boat that give a smooth, finished appearance while still permitting the passage of a significant amount of seawater.

Circuit Breaker - An electromechanical switching unit intended to prevent the flow of electricity under normal operating conditions and, in the case of a short circuit, to permit the electrification of all conductive metal fittings throughout the boat. Available at most novelty shops.

Club, Yacht Club, Racing Association - Troublesome seasonal accumulation in coastal areas of unpleasant marine organisms with stiff necks and clammy extremities. Often present in large numbers during summer months when they clog inlets, bays, and coves, making navigation almost impossible. The infestations are most serious along the coasts of Connecticut, Massachusetts, and Maine. They can be effectively dislodged with dynamite, but, alas, archaic federal laws rule out this option.

Course - The direction in which a skipper wishes to steer his boat and from which the wind is blowing. Also, the language that results by not being able to do this.

Crew - Heavy, stationary objects used on shipboard to hold down charts, anchor cushions in place and dampen sudden movements of the boom.

Cruising - Waterborne pleasure journey embarked on by one or more people. A cruise may be considered successful if the same number of individuals who set out on it arrive, in roughly the same condition they set out in, at some piece of habitable dry land, with or without the boat.

Current - Tidal flow that carries a boat away from its desired destination, or toward a hazard.

Distress Signals - International signals which indicate that a boat is in danger. For example, in American waters: the sudden appearance of lawyers, the pointing of fingers, and repression of memories.

Engine - Sailboats are equipped with a variety of engines, but all of them work on the internal destruction principle, in which highly machined parts are rapidly converted into low-grade scrap, producing in the process energy in the form of heat, which is used to boil bilge water; vibration, which improves the muscle tone of the crew; and a small amount of rotational force, which drives the average size sailboat at speeds approaching a furlong per fortnight.

Equator - A line circling the earth at a point equidistant from both poles that separates the oceans into the North Danger Zone and the South Danger Zone.

Etiquette: Marine custom establishes a code of social behavior and nautical courtesy for every conceivable occasion. Thus, for example, a boat belonging to another boatman is always referred to as a "scow", a "tub", or a "pig-boat". When one skipper goes aboard another's boat, he does not hesitate to tell him frankly about any drawbacks or disadvantages he finds in comparison to his own craft. Sailors welcome every opportunity to improve their vessels, and so he knows that his remarks will be greatly appreciated. When one sailboat passes another, it is customary for the captain of the passing boat to make a bladder like sound with his lips and tongue, and for the captain of the passed boat to return the courtesy by offering a smart salute consisting of a quick upward movement of the right hand with the second digit extended.

Figurehead - Decorative dummy found on sailboats. See Captain.

Privileged Vessel - The vessel which, in a collision, was "in the right". If there were witnesses, the owner could bring an admiralty court case - know as a "wet suit" or a "leisure suit" - against the owner of the other boat, and if he proves "whiplash", he could collect a tidy sum.

Flag - Any of a number of signaling pennants or ensigns, designed to be flown upside down, in the wrong place, in the wrong order, or at an inappropriate time.

Flashlight - A tubular metal container used on shipboard for storing dead batteries prior to their disposal.

Fluke - The portion of an anchor that digs securely into the bottom, holding the boat in place. Also, any occasion when this occurs on the first try.

Why did pirates make prisoners walk the plank when they could've just tossed them overboard?

 You've got the instincts of a pirate all right. It turns out that they did toss them overboard, and they didn't really make them walk the plank. The walking-the-plank myth was first introduced in Robert Louis Stevenson's classic "Treasure Island" and has since been reinforced by pirate literature from "Peter Pan to Captain Blood." (Stevenson was also the source for the most famous, yet completely fictitious, pirate song that goes "Sixteen men on a dead man's chest / Yo-ho-ho and a bottle of rum ...") Besides tossing victims overboard, typical punishments by real pirates included: "Flogging". This treatment was universally popular at the time, on and off the high seas. "Man Overboard". While this could be as simple as merely tossing the captive or prisoner overboard, it was sometimes varied to relieve the boredom of a long trip. Sometimes a manwould be tied to one end of a rope and dragged until he died from drowning or exhaustion. Perhaps this was how waterskiing was invented.  "Dunking". This was less popular, as it required dunking the prisoner then hoisting him back up again, suspending him for hours above the water. It was too time-consuming, and aside from the initial spluttering and choking, not that entertaining. "Marooning". This was the most common form of punishment for serious offenses like desertion. A sailor was either placed on a raft or left on a deserted island to die. If left in the water, he was often mercifully given a pistol to kill himself before the sharks got him.

~source used: "Just Curious About History, Jeeves"by Erin Barrett & Jack Mingo

A nautical mile is a distance on the earth's surface of 6,080 feet, which is equal to one minute of latitude at the earth's equator. Since there are 360 degrees around the earth, and each degree equals 60 minutes, the distance around the earth, at the equator or any other great circle, is 21,600 nautical miles. (A great circle is like a diameter.)

The origin of the nautical mile started with the realization that the earth was spherical and not flat. It was Pythagoras who first put forward the theory in 580 b.c.

For more information, check out The History of Navigation.Have fun with our calculator that converts statute miles to nautical miles, and vice versa.