Rudder in the context of Tiller

A ship's wheel or boat's wheel is a device used aboard a ship, boat, submarine, or airship, with which a helmsman steers the vessel and controls its course. Together with the rest of the steering mechanism, it forms part of the helm (the term helm can mean the wheel alone, or the entire mechanism by which the rudder is controlled). It is connected to a mechanical, electric servo, or hydraulic system which alters the horizontal angle of the vessel's rudder relative to its hull. In some modern ships the wheel is replaced with a simple toggle that remotely controls an electro-mechanical or electro-hydraulic drive for the rudder, with a rudder position indicator presenting feedback to the helmsman.

A junk (Chinese: 䑸; pinyin: zōng) is a type of Chinese sailing ship characterized by a central rudder, an overhanging flat transom, watertight bulkheads, and a flat-bottomed design. They are also characteristically built using iron nails and clamps. The term applies to many types of small coastal or river ships, usually serving as cargo ships, pleasure boats, or houseboats, but also going up in size up to large ocean-going vessels. There can be significant regional variations in the type of rig and the layout of the vessel.

Chinese junks were originally only fluvial and had square sails, but by the Song dynasty (c. 960 to 1279), they adopted ocean-going technologies acquired from Southeast Asian k'un-lun po trade ships. Tanja sails and fully battened junk rigs were introduced to Chinese junks by the 12th century CE.

A vertical stabilizer or tail fin is the static part of the vertical tail of an aircraft. The term is commonly applied to the assembly of both this fixed surface and one or more movable rudders hinged to it. Their role is to provide control, stability and trim in yaw (also known as directional or weathercock stability). It is part of the aircraft empennage, specifically of its stabilizers.

The vertical tail is typically mounted on top of the rear fuselage, with the horizontal stabilizers mounted on the side of the fuselage (a configuration termed "conventional tail"). Other configurations, such as T-tail or twin tail, are sometimes used instead.

An iceboat (occasionally spelled ice boat or traditionally called an ice yacht) is a recreational or competition sailing craft supported on metal runners for traveling over ice. One of the runners is steerable. Originally, such craft were boats with a support structure, riding on the runners and steered with a rear blade, as with a conventional rudder. As iceboats evolved, the structure became a frame with a seat or cockpit for the iceboat sailor, resting on runners. Steering was shifted to the front.

Because of their low resistance to forward motion over ice, iceboats are capable of speeds exceeding 60 miles per hour (100 km/h). Because of their speed, iceboats are used both for recreation and for racing. Racing craft typically carry one person.

The clarion (also rest or sufflue) is a rare charge in heraldry of uncertain meaning and purpose. It originates from England and is still largely exclusive to that country, though latterly it has been imported to other Anglophone nations. In Canadian heraldry, it is the cadency mark of a ninth daughter.

It is generally said to represent a kind of wind instrument such as a panpipe or recorder, but does not resemble the trumpet-like clarion known to modern musicians. It may also be intended as an overhead view of a keyboard instrument such as a spinet. Alternatively it has been said to represent a 'rest', a device used by mediaeval knights to support a lance during jousting. In his Display of Heraldry John Guillim suggests that it may be a rudder. 'Clarion' is also the name given to a stop on an organ which imitates the sound of a trumpet.

Stays are ropes, wires, or rods on sailing vessels that run fore-and-aft along the centerline from the masts to the hull, deck, bowsprit, or to other masts which serve to stabilize the masts.

A stay is part of the standing rigging, (as opposed to a sheet (sailing), which is adjustable), and is used to hold a mast upright.

An outboard motor is a propulsion system for boats, consisting of a self-contained unit that includes engine, gearbox and propeller or jet drive, designed to be affixed to the outside of the transom. They are the most common motorised method of propelling small watercraft. As well as providing propulsion, outboards provide steering control, as they are designed to pivot over their mountings and thus control the direction of thrust. The skeg also acts as a rudder when the engine is not running. Unlike inboard motors, outboard motors can be easily removed for storage or repairs.

In order to eliminate the chances of hitting bottom with an outboard motor, the motor can be tilted up to an elevated position either electronically or manually. This helps when traveling through shallow waters where there may be debris that could potentially damage the motor as well as the propeller. If the electric motor required to move the pistons which raise or lower the engine is malfunctioning, every outboard motor is equipped with a manual piston release which will allow the operator to drop the motor down to its lowest setting.

A hydroplane (or hydro, or thunderboat) is a fast motorboat, where the hull shape is such that at speed, the weight of the boat is supported by planing forces, rather than simple buoyancy.

A key aspect of hydroplanes is that they use the water they are on for lift rather than buoyancy, as well as for propulsion and steering: when travelling at high speed water is forced downwards by the bottom of the boat's hull. The water therefore exerts an equal and opposite force upwards, lifting the vast majority of the hull out of the water. This process, happening at the surface of the water, is known as 'foiling'.

A vortex generator (VG) is an aerodynamic device, consisting of a small vane usually attached to a lifting surface (or airfoil, such as an aircraft wing) or a rotor blade of a wind turbine. VGs may also be attached to some part of an aerodynamic vehicle such as an aircraft fuselage or a car. When the airfoil or the body is in motion relative to the air, the VG creates a vortex, which, by removing some part of the slow-moving boundary layer in contact with the airfoil surface, delays local flow separation and aerodynamic stalling, thereby improving the effectiveness of wings and control surfaces, such as flaps, elevators, ailerons, and rudders.

A Landing Ship, Tank (LST) is a ship first developed during World War II (1939–1945) to support amphibious operations by carrying tanks, vehicles, cargo, and landing troops directly onto a low-slope beach with no docks or piers. The shallow draft and bow doors and ramps enabled amphibious assaults on almost any beach.

The LST had a highly specialized design that enabled ocean crossings as well as shore groundings. The bow had a large door that could open, deploy a ramp and unload vehicles. The LST had a flat keel that allowed the ship to be beached and stay upright. The twin propellers and rudders had protection from grounding. The LSTs served across the globe during World War II, including in the Pacific War and in the European theater.

The gondola (English: /ˈɡɒndələ/, Italian: [ˈɡondola]; Venetian: góndoła, Venetian: [ˈɡoŋdoɰa]) is a traditional, flat-bottomed Venetian rowing boat, well suited to the conditions of the Venetian lagoon. It is typically propelled by a gondolier, who uses a rowing oar, which is not fastened to the hull, in a sculling manner, and also acts as the rudder. The uniqueness of the gondola includes its being asymmetrical along the length, making the single-oar propulsion more efficient.

For centuries, the gondola was a major means of transportation and the most common watercraft within Venice. In modern times, the boats still do have a role in public transport in the city, serving as traghetti (small ferries) over the Grand Canal operated by two oarsmen.

A transom is the aft transverse surface of the hull of some boats and ships forming its stern. Adding both strength and width to the stern, a transom may be flat or curved, and vertical, raked aft (known as an overhung or "counter" stern), or raked forward (and "reversed", also known as retroussé). In small boats and yachts, a flat termination of the stern is typically above the waterline, but large commercial vessels often exhibit vertical transoms that dip slightly beneath the water.

On smaller boats such as dinghies, transoms may be used to support a rudder, outboard motor, or other accessory. On some yachts the transom may include a hinged swim platform, and a lazarette for deck items and leisure toys.

On a sailing vessel, a forestay, sometimes just called a stay, is a piece of standing rigging which keeps a mast from falling backwards. It is attached either at the very top of the mast, or in fractional rigs between about 1/8 and 1/4 from the top of the mast. The other end of the forestay is attached to the bow of the boat.

Often a sail is attached to the forestay. This sail may be a jib or a genoa. In a cutter rig, the jib or jibs are flown from stays in front of the forestay, perhaps going from the masthead to a bowsprit. The sail on the forestay is then referred to as the staysail or stays'l.

A gubernaculum in classical references describes a ship's rudder or steering oar. The English word government is related to the word. The Old English word governail and the Scots word gouernaill are both derived from it.

Fly-by-wire (FBW) is a system that replaces the conventional manual flight controls of an aircraft with an electronic interface. The movements of flight controls are converted to electronic signals, and flight control computers determine how to move the actuators at each control surface to provide the ordered response. Implementations either use mechanical flight control backup systems or else are fully electronic.

Improved fully fly-by-wire systems interpret the pilot's control inputs as a desired outcome and calculate the control surface positions required to achieve that outcome; this results in various combinations of rudder, elevator, aileron, flaps and engine controls in different situations using a closed feedback loop. The pilot may not be fully aware of all the control outputs acting to affect the outcome, only that the aircraft is reacting as expected. The fly-by-wire computers act to stabilize the aircraft and adjust the flying characteristics without the pilot's involvement, and to prevent the pilot from operating outside of the aircraft's safe performance envelope.

An aircraft in flight is free to rotate in three dimensions: yaw, nose left or right about an axis running up and down; pitch, nose up or down about an axis running from wing to wing; and roll, rotation about an axis running from nose to tail. The axes are alternatively designated as vertical, lateral (or transverse), and longitudinal respectively. These axes move with the vehicle and rotate relative to the Earth along with the craft. These definitions were analogously applied to spacecraft when the first crewed spacecraft were designed in the late 1950s.

These rotations are produced by torques (or moments) about the principal axes. On an aircraft, these are intentionally produced by means of moving control surfaces, which vary the distribution of the net aerodynamic force about the vehicle's center of gravity. Elevators (moving flaps on the horizontal tail) produce pitch, a rudder on the vertical tail produces yaw, and ailerons (flaps on the wings that move in opposing directions) produce roll. On a spacecraft, the movements are usually produced by a reaction control system consisting of small rocket thrusters used to apply asymmetrical thrust on the vehicle.

Flight control surfaces are aerodynamic devices allowing a pilot to adjust and control the aircraft's flight attitude. The primary function of these is to control the aircraft's movement along the three axes of rotation. Flight control surfaces are generally operated by dedicated aircraft flight control systems.

Development of an effective set of flight control surfaces was a critical advance in the history of development of aircraft. Early efforts at fixed-wing aircraft design succeeded in generating sufficient lift to get the aircraft off the ground, however with limited control. The development of effective flight controls allowed stable flight.