CoracleA coracle is a small, rounded, lightweight boat of the sort traditionally used in Wales, and also in parts of the West Country and in Ireland, particularly the River Boyne, and in Scotland, particularly the River Spey. The word is also used of similar boats found in India, Vietnam, Iraq, and Tibet. The word coracle is an English spelling of the original Welsh cwrwgl, cognate with Irish and Scottish Gaelic currach, and is recorded in English text as early as the sixteenth century.
Port and starboardPort and starboard are nautical terms for watercraft, aircraft and spacecraft, referring respectively to the left and right sides of the vessel, when aboard and facing the bow (front). Vessels with bilateral symmetry have left and right halves which are s of each other. One asymmetric feature is where access to a boat, ship, or aircraft is at the side, it is usually only on the port side (hence the name). Port and starboard unambiguously refer to the left and right side of the vessel, not the observer.
SuperstructureA superstructure is an upward extension of an existing structure above a baseline. This term is applied to various kinds of physical structures such as buildings, bridges, or ships. On water craft, the superstructure consists of the parts of the ship or a boat, including sailboats, fishing boats, passenger ships, and submarines, that project above her main deck. This does not usually include its masts or any armament turrets. Note that in modern times, turrets do not always carry naval artillery, but they can also carry missile launchers and/or antisubmarine warfare weapons.
Diesel engineThe diesel engine, named after Rudolf Diesel, is an internal combustion engine in which ignition of the fuel is caused by the elevated temperature of the air in the cylinder due to mechanical compression; thus, the diesel engine is called a compression-ignition engine (CI engine). This contrasts with engines using spark plug-ignition of the air-fuel mixture, such as a petrol engine (gasoline engine) or a gas engine (using a gaseous fuel like natural gas or liquefied petroleum gas).
RaftA raft is any flat structure for support or transportation over water. It is usually of basic design, characterized by the absence of a hull. Rafts are usually kept afloat by using any combination of buoyant materials such as wood, sealed barrels, or inflated air chambers (such as pontoons), and are typically not propelled by an engine. Rafts are an ancient mode of transport; naturally-occurring rafts such as entwined vegetation and pieces of wood have been used to traverse water since the dawn of humanity.
Ship's tenderA ship's tender, usually referred to as a tender, is a boat or ship used to service or support other boats or ships. This is generally done by transporting people or supplies to and from shore or another ship. A second and distinctly different meaning for "tender" is small boats carried by larger vessels, to be used either as lifeboats, or as transport to shore, or both. For a variety of reasons, it is not always advisable to try to tie a ship up at a dock; the weather or the sea might be rough, the time might be short, or the ship too large to fit.
SeakeepingSeakeeping ability or seaworthiness is a measure of how well-suited a watercraft is to conditions when underway. A ship or boat which has good seakeeping ability is said to be very seaworthy and is able to operate effectively even in high sea states. In 1976, St. Denis suggested four principal terms needed to describe a seakeeping performance. These are: Mission: what the ship is intended to accomplish. The role of the ship while at sea. Environment: the conditions under which the ship is operating.
NarrowboatA narrowboat is a particular type of canal boat, built to fit the narrow locks of the United Kingdom. The UK's canal system provided a nationwide transport network during the Industrial Revolution, but with the advent of the railways, commercial canal traffic gradually diminished and the last regular long-distance transportation of goods by canal had virtually disappeared by 1970. However, some commercial traffic continued. From the 1970s onward narrowboats were gradually being converted into permanent residences or as holiday lettings.
MultihullA multihull is a boat or ship with more than one hull, whereas a vessel with a single hull is a monohull. The most common multihulls are catamarans (with two hulls), and trimarans (with three hulls). There are other types, with four or more hulls, but such examples are very rare and tend to be specialised for particular functions. Counter-intuitively, it is unhelpful to think of the design progression to be "1-2-3", namely monohull - catamaran - trimaran; rather, it is "1-3-2".
TugboatA tugboat or tug is a marine vessel that manoeuvres other vessels by pushing or pulling them, with direct contact or a tow line. These boats typically tug ships in circumstances where they cannot or should not move under their own power, such as in crowded harbors or narrow canals, or cannot move at all, such as barges, disabled ships, log rafts, or oil platforms. Some are ocean-going, and some are icebreakers or salvage tugs. Early models were powered by steam engines, which were later superseded by diesel engines.
