Do not pass ahead of me
Tabernacle, Tack, Tack purchase, Tack tackle, Tackle, Taffrail, Tallow, Tar, Tarp, Tarpaulin, Telescope, Tell-tale, Temperature, Tender, Tether, TEV, Thames tonnage, Thole pins, Throat, Thwart, Tidal height, Tidal stream, Tide, Tide gauge, Tiller, Timber, Time, Tingle, Toerail, Toe the line, Tompion, Tonnage, Top, Topgallant, Tophamper, Topmast, Topping lift, Topsail, Topsides, Touch and go, Tow, Towing, Tradewinds, Traffic separation scheme, Trailer, Trailer-sailer, Transceiver, Transit, Transom, Traveller, Trawler, Treenail, Trestle trees, Triangle, Triatic, Trice, Trick, Tricolour, Trim, Trimaran, Tripping line, Trireme, Trot, Truck, True bearing, True North, Trysail, TSS, Tug, Tumblehome, Turn, Turnbuckle, Tye
The mast of the half-tonner to the right pivots in a tabernacle. The cover in the foredeck between the skipper's feet can be removed; the mast pivots aft, the heel of the mast pivots forward and upward through the space left by removing the cover. A lead weight is attached to the heel of the mast as a counterbalance and contributes to the ballast of the boat.
n The foremost lower corner of the sail.
n A sailing boat is on port tack when the wind is on its port side; it is on the starboard tack when the wind is on its starboard side. This is (was) because on a square-rigged vessel the tack of the course sail would be pulled hard down (tacked down) to the port bow when the wind was on the port side of the vessel.
n A small sharp nail, with a broad head, for tacking down loose carpet. Joshua Slocum scattered them around his decks when asleep at anchor so that barefoot boarding thieves would make a lot of noise.
Hard tack: see biscuit.
Not a downhaul.
See tack purchase
A rendered form of beef or mutton fat, a soft solid at room temperature but with no clear melting point.
Tar is a dark brown or black viscous liquid of hydrocarbons and free carbon, obtained from coal, wood, petroleum, or peat by destructive distillation. Production and trade in pine-derived tar was once a major contributor to the economies of Northern Europe and Colonial America. Its main use was in preserving wooden sailing vessels and hemp rigging against rot. The largest user was the Royal Navy. Demand for tar declined with the advent of iron and steel ships.
American slang for tarpaulin (sheet)
A compound noun derived, and corrupted, from two words, tar and palling: palling is material (originally canvas) used to cover items and protect them from the weather. Tarred palling (tarpaulin) was canvas impregnated with tar to make it waterproof.
In other contexts, a pall is a cloth used to cover a coffin, or a piece of linen used to cover a chalice.
Modern (21st century) tarpaulin is made from a variety of plastics.
An optical instrument, used with only one eye, for seeing long distances. The combination of lenses makes distant objects seem nearer and bigger.
The monocular (sic) is the modern equivalent.
Commercially available tell-tales have self-adhesive patches which stick to a sail close to the luff and which have a length of light yarn attached. They are sold in pairs, oftened coloured green for the starboard side of the sail and red for the port side.
Not a 'tell-tail', although the short length of coloured yarn may look like a tail.
n Someone who reveals a 'friend's' misdeeds.
Temperature is a measure of the hotness or coldness of objects; for a given object it is proportional to the heat content of the object. Atmospheric air is sufficiently homogeneous that its temperature reflects its heat content.
Pure water freezes at a temperature of 0°Celcius, and boils at 100°Celcius. Sea water freezes at about -2°C. An object at a temperature of 50°C feels warm to the touch; at 60°C it is too warm to hold.
The temperature of the sea depends partly on the latitude (warmer at lower latitudes and colder at higher latitudes), partly on heat from the core of the earth and partly on heat exchange with the air above it.
The ocean currents move not only water from place to place but heat as well. For example, the Gulf Stream and the North Atlantic Drift move warmer water from the Caribbean to Northern Europe, so that the water around the British Isles is warmer than the water of Labrador at the same latitude in the Western Atlantic.
Air temperature is affected partly by the heat from the core of the earth, partly by exchange of heat with the sea, but largely by radiant heat from the sun. The tropics are warmer than the poles because the intensity of radiation per unit area is greater at the Equator than it is at the poles.
Warmer air is less dense than colder air, so a warmer air mass rises above a colder air mass.
Falling, colder air rotates clockwise in the Northern Hemisphere, creating gentle anticyclonic winds and stable air masses. Rising, warmer air rotates anticlockwise in the Northern Hemisphere, creating cyclonic winds up 100 knots and unstable air.
Sailors feel more comfortable at air and water temperatures between 18 and 28°C than they do at warmer or colder temperatures. Sailors who fall into water below about 10°C survive for shorter times than those who fall into warmer waters.
(The terms 'colder' and 'warmer' are relative; the Azores High is caused by falling, colder air at temperatures around 25°C. The rising, warmer air of a North Atlantic frontal system may be as low as 10°C)
n The smaller vessel which carries crew and stores from the quay to the boat and back. A cruise ship may carry a number of tenders, which may be substantial power-driven vessels. A yacht may carry an inflatable boat, with oars or an outboard engine.
A tender tends to the parent vessel's needs.
The three point attachment strap for use with a harness or lifejacket. It has a carabiner or snap hook on each of the three ends of the strap; one attaches to the sailor's harness or life jacket, another to a strong point on the boat.
Turbo electric vessel.
A measure of the volume, or carrying capacity, of a boat, where
TT = (length - beam) x (beam x beam) / 188.
length and beam are measured in feet
It is not an estimate of the weight, or displacement of a vessel.
The rise of tide is the distance, in metres, which the tide has risen between two chosen times, often between the previous low water and the present time, or between the present time and the next high water.
It might also tell you whether the car park will flood before you get back to your car.
The fall of tide is the distance, in metres, which the tide falls between two chosen times. It helps you to calculate whether your boat will still be afloat at the next low water.
In the open sea tidal streams may be circular, but will depend on the shape of the tidal basin.
It is characterised by three arrow heads part way along the line.
Tidal Streams are measured in one-hour intervals, relative to High Water at the Reference port. It is assumed (although, of course, it’s not so) that the set and drift remain constant throughout the tidal hour and then change abruptly at the beginning of the next tidal hour.
Tides (from low-German 'tiet' = 'time') are the rise and fall of sea levels caused by the combined effects of the gravitational forces exerted by the Moon and the Sun and the rotation of the Earth.
Most places in the ocean usually experience two high tides and two low tides each day (semi-diurnal tide), but some locations experience only one high and one low tide each day (diurnal tide). The times and amplitude of the tides at the coast are influenced by the alignment of the Sun and Moon, by the pattern of tides in the deep ocean and by the shape of the coastline and near-shore bathymetry.
Tide changes proceed in the following stages:
Sea level rises over several hours, covering the intertidal zone; this is the flood tide.
The water rises to its highest level, reaching high tide (High Water (HW)).
Sea level falls over several hours, revealing the intertidal zone; this is the ebb tide.
The water stops falling, reaching low tide (Low Water (LW)).
The range of a tide is the difference between Height of Tide at HW and Height of Tide at LW.
As the tide rises it moves to cover the intertidal zone: as it falls it moves to uncover the intertidal zone. These oscillating horizontal movements are known as tidal streams. The moment that the tidal stream ceases is called slack water or slack tide. The tidal stream then reverses direction and is said to be turning. Slack water usually occurs near high water and low water, but there are locations where the moments of slack tide differ significantly from those of high and low water.
Many factors contribute to the tides: the primary constituents are the Earth's rotation, the positions of the Moon and the Sun relative to Earth, the Moon's altitude (elevation) above the Earth's equator, and the shape of the basin in which the tide is moving.
The semi-diurnal range (the difference in height between high and low waters over about half a day) varies in a two-week cycle. Approximately twice a month, around new moon and full moon when the Sun, Moon and Earth form a line, the tidal force due to the sun reinforces that due to the moon. The tide's range is then at its maximum: this is called the spring tide.
When the Moon is at first quarter or third quarter, the sun and moon are separated by 90° when viewed from the Earth, and the solar tidal force partially cancels the moon's. At these points in the lunar cycle, the tide's range is at its minimum: this is called the neap tide.
Spring tides result in high waters that are higher than average, low waters that are lower than average, 'slack water' time that is shorter than average and stronger tidal streams than average. Neaps result in less extreme tidal conditions. There is about a seven-day interval between springs and neaps.
There is a delay between the phases of the moon and the effect on the tide. Springs and neaps in the North Sea, for example, are two days behind the new/full moon and first/third quarter moon. This is called the tide's age.
The local bathymetry (the shape and size of the basin) greatly influences the tide's exact time and height at a particular coastal point. There are some extreme cases: the Bay of Fundy, on the East coast of Canada, features the world's largest well-documented tidal ranges, 17 metres (56 ft), because of its shape.
Parts of the South Coast of the United Kingdom (between Chichester and Poole) have a double high water caused by the interaction between the region's different tidal harmonics, caused primarily by the east/west orientation of the English Channel and the fact that when it is high water at Dover it is low water at Land's End (some 300 nautical miles distant) and vice versa. This is contrary to the popular belief that the flow of water around the Isle of Wight creates two high waters. The Isle of Wight is important, however, since it is responsible for the 'Young Flood Stand', which describes the pause of the incoming tide about three hours after low water.
Because the oscillation modes of the Mediterranean Sea and the Baltic Sea do not coincide with any significant astronomical forcing period, their tides have a small range, the largest being close to their narrow connections with the Atlantic Ocean and the North Sea. Extremely small tides also occur for the same reason in the Gulf of Mexico and Sea of Japan. Elsewhere, as along the southern coast of Australia, small tides can be due to the presence of a nearby amphidrome.
The tidal effects observed along the Menai Strait can also be confusing. A rising tide approaches from the south-west, causing the water in the strait to flow north-eastwards as the level rises. The tide also flows around Anglesey until, after a few hours, it starts to flow into the strait in a south-westerly direction from Beaumaris. By the time this happens the tidal flow from the Caernarfon end is weakening and the tide continues to rise in height but the direction of tidal flow is reversed.
A similar sequence is seen in reverse on a falling tide. This means that slack water between the bridges tends to occur approximately one hour before high tide or low tide.
Theoretically it is possible to ford the strait in the Swellies at low water, spring tides when the depth may fall to less than 0.5 metres (1.6 ft). However, at these times a strong tidal stream of around 5 knots is running, making the crossing extremely dangerous. Elsewhere in the strait the minimum depth is never less than 2 metres (6.6 ft) except at the great sand flats at Lavan Sands, N'East of Bangor.
The height of the tide is measured in metres above chart datum, and is recorded alongside the times of High Water and Low Water in a tide table.
The direction of the horizontal movement of the water (the set of the tide) is measured in °True. The speed of the stream (the drift of the tide) is measured in knots. The set and drift are recorded in tables of tidal diamonds on the chart and in tidal stream atlases.
An experimental tide-powered turbine has been built in the entrance to Strangford Lough, in Northern Ireland.
n Unprocessed wood cut from the tree.
There are 24 hours in a day, from midnight to midnight.
Conventional clocks show only 12 hours (midnight to midday and midday to midnight), but nautical time is measured by the 24-hour clock. Midnight is 0000; 6 am is 0600; midday (noon) is 1200; 6pm is 1800; 1 minute before midnight is 2359.
Midnight to 0600 is morning; 0600 to noon is the forenoon; noon to 1800 is afternoon; 1800 to midnight is evening. See Watches.
There are 60 minutes in every hour and 60 seconds in every minute: minutes of time are not to be confused with minutes of angle (of which there are 60 in every degree).
The Earth rotates from West to East 360 angular degrees in every 24 hours of time, or 15° every hour; the Sun therefore appears to move from East to West.
The world is divided (theoretically) into 24 time zones. Theoretically, the time in each time zone is 1200 (noon) when the sun is directly overhead. (For a map of the time zones, see Universal Time)
But two things distort this.
First, the sun may be early, or late, overhead by as much as 12 minutes.
Second, certain countries opt to belong to a time zone to which geographically they should not belong. For example, France has chosen to align its clocks to Central European time, which is one hour to the East of its geographical position. As another example, Iceland has chosen to align its clocks to GMT, even though it lies one time zone to the West.
The Greenwich Meridian (the Prime Meridian) is an imaginary line through the North Pole, Greenwich (in East London) and the South Pole. It lies at the middle of time zone 0000, which extends from Longitude 7.5° West to Longitude 7.5° East. When the sun is (on average) overhead Greenwich the time is 1200GMT throughout the time zone.
The middle of the Central European Time Zone is 15° to the East of the Prime Meridian. In terrestrial notation it is time zone (UT + 1); in nautical notations it is time zone -0100.
See Universal Time
Toe the line. See Line.
"Do as you're told"
A wooden plug inserted into the end of a gun barrel to keep the barrel dry and delay corrosion.
Tonnage See Thames Tonnage
Platforms at the junctions of the parts of a mast.
They serve to spread as far apart as possible the shrouds for the next part of the mast. Tops are held from below by futtock shrouds. On fighting ships the tops also served as platforms for archers, later for musketmen, who would shoot down at the officers on the quarter deck of the enemy ship. At the Battle of Trafalgar Admiral Nelson was killed by a sniper firing from the fighting top of Redoubtable.
The ship on the right is The Amsterdam, moored in Amsterdam harbour. The foremast, mainmast and mizzenmast shrouds can be seen clearly. The foretop, maintop and mizzentop can be seen. The main topmast shrouds and the fore topmast shrouds can be seen. The fore topgallant shrouds can be seen, as can the main and fore futtock shrouds.
Photograph by Margaret Starkie
The Amsterdam, in Amsterdam harbour
The line which sustains the weight of the end of the boom, and by hauling on which the end of the boom can be raised to the required height, or supported while the sail is reefed or handed or scandalised.
The photograph shows a schooner with a square-rigged topsail suspended from a square yard, similar to the topsail of a square-rigged vessel: the photograph also shows a crossjack yard to spread the foot of the sail.
Touch and go
The expression is now applied to any situation where stopping is either momentary or abandoned.
Trainee aircraft pilots practice 'touch and go' landings to save time and fuel.
n The vessel being towed.
One or more tugs may have warps to a larger vessel and guide it into harbour and a berth. One or more of the tugs may push the larger vessel. Those tugs ahead of the larger vessel pull it forward. Those astern or alongside steer the larger vessel.
A tug may push a train of barges or lighters to which it is securely attached.
A lifeboat may tow a stricken vessel back to harbour
A friendly boat may tow a broken-down boat back to harbour.
There are three ways in which vessels might be towed.
1 In line astern on a long or a short warp.
Yachts which are normally anchored or moored in the roadstead (rather than berthed in a marina) need a dinghy (tender) to get the crew to and from the boat. On passage, the yacht might tow the dinghy astern. At sea, many skippers prefer a long warp so that the dinghy does not bump against the yacht's stern. At close quarters a long warp becomes a nuisance, partly because if the yacht reverses its engine the warp may become caught in the propeller. For this reason many skippers use a very short warp, which is bright yellow and which floats.
The tow has a line from its stern quarter to a cleat amidships the tug; it is this line which tows. The line from the tow's bow to the tug's bow (a breastrope) is simply to keep the tow alongside; properly adjusted, it may allow the tow's head to fall away from the tug and keep the two vessels slightly apart. A breastrope from the tug's stern to the tow's stern keeps the tow the correct distance from the tug.
3 By pushing.
The stems of most commercial harbour tugs are adapted for pushing. The barges or lighters to be pushed are tightly and securely attached to the tug so that the two (or many) behave as a single vessel.
The tugs which manoeuvre large ships in harbour are similarly adapted, but are not normally attached to the ship when pushing.
At the Equator warmer, less dense air rises to a height of, perhaps, 11 kilometres. Some of the air moves North, some moves South at altitude. At latitude 30 or 40°N (and S) this air falls (as colder air). At the surface it moves South (and North) to replace the rising, warmer Equatorial air. As it moves, the Coriolis Force, resulting from the rotation of the Earth, displaces the surface air to the West, causing an Easterly wind.
Traffic Separation Scheme
A means of keeping apart large vessels travelling in opposite directions in busy, but deep, waters. Corridors or lanes to which large vessels are constrained in the open sea. The beginning and end of a separation scheme may be marked with Special buoys or Safe Water Marks but the corridors, or lanes, are defined by GNSS, occasionally by Channel Markers. Not to be confused with channels.
See IRPCS Rule 10
See TSS, below.
A boat which can be drawn on a trailer from one cruising water to another.
Almost any boat can be carried on a road trailer, but larger boats are more difficult to lift out of and into the water than smaller boats; dinghies are relatively easy. Trailer-sailers are larger than most dinghies and usually have an enclosed cabin. They may be up to 30 feet (9m) in length and rarely less than eighteen (5.5m). They often have a centreboard or. more rarely, one or more daggerboards or occasionally leeboards.
Both a transmitter and a receiver.
The transceiver of an echo sounder transmits sound waves and receives the echoes.
When two features in sight of the boat are in line, on the same bearing. The most useful of all aids to pilotage. When two features can be seen in line the boat must be somewhere on the extended line.
Many harbours and ports have lights and/or posts (see leading line) which form a transit for safe entry to the harbour. Leading lines, and the characteristics of their lights and shapes, are shown on charts.
Skippers of small boats often establish their own transits using features such as trees, buildings, pylons.
In the USA a transit is known as a range.
n The flat or curved, vertical or sloping part of the boat at the stern from the deck to the waterline (and below).
n A transverse horizontal structural beam or bar, typically above a door. In the Age of Sail the transoms of a ship were the horizontal beams which, together with the fashion pieces, formed the framework for the stern of a ship.
n A person who travels.
A mathematical figure with three sides. The sides are lines which might be straight or curved.
A vector is a straight line (on paper) representing both direction and magnitude. The angle which the line has with a linear datum (True North when drawn on a chart) gives the direction; the length of the line gives the magnitude.
The three lines of a triangle of vectors are Heading & Speed (through the water) of the boat, Set & Drift of the tide, Direction & Speed over the ground. When drawn on a chart the triangle represents a fixed period of time (perhaps one hour to correspond with a tidal hour) so that Speed is reduced to distance within the fixed period of time.
In calculating a Course to Steer one vector (tidal Set and Drift) is known; parts of the other two (Course over the ground and boat Speed through the water) are known, and are used to calculate the boat's Heading and its Speed over the ground.
In Estimating a future Position two vectors (tidal Set and Drift, and boat Heading and Speed) are known; they are used to calculate the Course over the ground and Speed over the ground.
A brass triangle on the deck of a Ship of the Line was supposed to carry a pile of 4 cannon balls; one in each corner of the triangle and one on top. The brass triangle may have been known as a monkey.
A nautical myth suggests that in very cold weather the brass monkey would contract more than the iron balls and then the balls would roll off the monkey.
In fact, the coefficient of expansion (or contraction) of brass with heat (or cold) is not so different from that of iron that this could happen within the temperature range compatible with the life of the crew.
There is little evidence that brass triangles were used to hold cannon balls on deck; balls were usually held in wooden racks (garlands).
Usually corrupted to tr'n'l, and pronounced either 'trunnel' or 'trennel'.
A running light allowed on sailboats less than 20m long instead of the normal side and stern lights. The tricolor light contains the red and green side lights and the white stern light in a single fitting that is attached to the top of the mast. This is neither a ‘masthead light’ nor an all-round light.
IRPCS Rule 25, “Sailing vessels underway and vessels under oars” says:
(a) A sailing vessel underway shall exhibit:
(ii) a sternlight.
(b) In a sailing vessel of less than 20 metres in length the lights prescribed in paragraph (a) of this Rule may be combined in one lantern carried at or near the top of the mast where it can best be seen.”
Rule 21 “Definitions” says:
“(b) "Sidelights” means a green light on the starboard side and a red light on the port side each showing an unbroken light over an arc of the horizon of 112.5 degrees and so fixed as to show the light from right ahead to 22.5 degrees abaft the beam on its respective side. . . .
(c) “Sternlight” means a white light placed as nearly as practicable at the stern showing an unbroken light over an arc of 135 degrees and so fixed as to show the light from 67.5 degrees from right aft on each side of the vessel.”
The advantage for a small sailing boat is that a single bulb in a tricolour fitting uses less power than 3 separate bulbs in 3 separate fittings. Power-hungry incandescent bulbs can now be replaced with Light Emitting Diodes, which use relatively little power.
vb To adjust the sails so as to utilize their maximum efficiency.
From this perspective there are just two points of sail: hard on the wind and off the wind. With the boat hard on the wind (close-hauled) the sheets are hauled in closely and the helmsman adjusts the heading to give best speed or best angle to the wind. With the boat off the wind (reaching or running) the helmsman steers a compass course while the crew trims the sails for best speed and efficiency.
vb To adjust the horizontal attitude of the boat for maximum speed through the water.
Many power boats are fitted with trim tabs below water on the transom to adjust the trim of the boat while under power.
Racing yachtscrew will often sit on the windward rail in a futile attempt to reduce the heel of their boat.
adj Tidy. Smart. Pleasing to the eye. 'Ship-shape and Bristol fashion'. "She's a trim little craft"
A sailing trimaran may have only two of the hulls in the water; the third, the windward hull, is 'flying'.
Three long, thin hulls offer less frictional resistance than a single large hull, so trimarans sail faster, or use less power, than monohulls.
A light line attached to the crown of an anchor close to the flukes; ie, at the opposite end to the attachment of the rode. The other end of the tripping line is attached to a buoy floating at the surface or to the boat.
See the photograph under Mooring.
Traffic Separation Scheme. Consult the IRPCS, Rule 10.
Rule 10 "Traffic separation schemes" says
"(a) This Rule applies to traffic separation schemes adopted by the Organization and does not relieve any vessel of her obligation under any other Rule. . .
(j) A vessel of less than 20 metres in length or a sailing vessel shall not impede the safe passage of a power-driven vessel following a traffic lane."
In the light of Rule 10(a), Rule 10(j) does not conflict with Rule 18(a).
Rule 18 "Responsibilities between vessels" says
Except where Rules 9,10 and 13 otherwise require
(a) A power-driven vessel underway shall keep out of the way of:
(i) a vessel not under command;
(ii) a vessel restricted in her ability to manoeuvre;
(iii) a vessel engaged in fishing;
(iv) a sailing vessel."
A ha'lyard runs from the heel of the mast to a sheave high on the mast, then down to a block near the gaff, and then back to fasten to a point high on the mast. The block acts as a purchase, halving the effort required to haul. The block is linked to the gaff by a tye.
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