Glossary
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TermDefinition
- General Nautical Terminology, Navigation Time Zone (TZ)
A region of the Earth where the same standard time is used.
A time zone is a geographical area that observes a uniform standard time for...
More Details - Flag Semaphore, Signals & Communication Letter T (Flag Semaphore)

Flag semaphore indicating the letter T.
- Morse Code, Signals & Communication Letter T (Morse Code)
International Morse Code sequence representing the letter T.
- General Nautical Terminology Toe Rail
A low, raised edge running along the outer perimeter of a boat's deck, designed to provide footing stability and prevent gear or crew from...
More Details - General Nautical Terminology Topping Lift
A line or wire used to support the boom of a sailboat when the sail is not hoisted, or to adjust the height of a spinnaker pole.
A topping...
More Details - General Nautical Terminology Topsides
The outer hull of a vessel above the waterline, extending from the deck to the water's edge.
The term "topsides" is a fundamental concept in...
More Details - General Nautical Terminology, Weather (Meteorology) Trafalgar
Sea area of the Met Office Shipping Forecast. Located off the southern coast of Spain, near Cape Trafalgar.
Named after Cape Trafalgar (site of...
More Details - General Nautical Terminology, Navigation Traffic Separation Scheme (TSS)
A navigation system designed to organise the flow of vessel traffic in congested or high-risk areas, ensuring safe passage by separating opposing...
More Details - General Nautical Terminology, Navigation Transit
An alignment of two fixed objects seen from the vessel.
This can be used as a simple and reliable visual reference for position, clearing...
More Details - General Nautical Terminology Transom
The transom is the flat, vertical surface at the back of a boat. It is typically where the outboard motor or stern drive is attached to a motor...
More Details - General Nautical Terminology, Parts of a Boat Traveller
A sliding fitting or track on a sailing vessel, used to adjust the position of a sail's sheet or other control lines for optimal sail...
More Details - General Nautical Terminology Tri-colour LightMasthead light combining red, green and white lights in one unit.
- General Nautical Terminology Trim
Trim is the adjustment of a boat's sails, weight distribution, and angle relative to the water to optimise performance, balance, and...
More Details - General Nautical Terminology TrimaranA vessel with three hulls
- General Nautical Terminology Trim TabsFlaps which can be pushed up or down to adjust the angles of the bow and heel on a motor vessel
- General Nautical Terminology, Organisation Trinity House
A maritime organisation responsible for maintaining navigational aids, including lighthouses and buoys, along England, Wales, and the Channel...
More Details - Weather (Meteorology) Tropical Hurricane
A tropical hurricane is an intense tropical cyclone characterised by strong winds, heavy rainfall, and low pressure. These storms typically form...
More Details - General Nautical Terminology, Navigation True North
The direction along the Earth's surface that points directly towards the geographic North Pole.
True North, also known as geographic north, is...
More Details - General Nautical Terminology True Wind
The wind experienced independently of a vessel’s own movement.
This is the actual movement of air over the water, as distinct from apparent...
More Details - General Nautical Terminology, Parts of a Boat, Safety Trysail
A small triangular sail hoisted at the masthead to help stabilise a boat in heavy winds.
A trysail is a small triangular sail that is hoisted...
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