"had raised platforms called ""castles"" at bow and stern that archers could occupy to fire down on enemy ships or even to drop heavy weights from. Over time these castles became higher and larger, and eventually were built into the structure of the ship, increasing overall strength. This aspect of the cog remained in the newer-style carrack designs and proved its worth in battles like that at Diu in 1509. The ""Mary Rose"" was an early 16th-century English carrack or ""great ship"". She was heavily armed with 78 guns and 91 after an upgrade in the 1530s. Built in Portsmouth"
"vessel, while stern refers to the ""outside"" (offboard) rearmost part of the vessel. The stern is opposite the bow, the ""outside"" (offboard) of the front of the boat. Aft Aft, in naval terminology, is an adjective or adverb meaning, ""towards the stern (rear) of the ship"", when the frame of reference is within the ship, headed at the fore. Example: ""Able Seaman Smith; lay aft!"". Or; ""What's happening aft?"" Aft also describes the direction of movement within an aircraft; that is, towards the tail. Example: ""Let's go aft"". Meaning to pull back on the yoke. It may also describe the"
"the water and widens as you go upwards. This is famous on many 19th century tea clippers and the ill-fated RMS ""Titanic"". A bustle stern refers to any kind of stern (transom, elliptical, etc.) that has a large ""bustle"" or blister at the waterline below the stern to prevent the stern from ""squatting"" when getting underway. It only appears in sailboats, never in power-driven craft. Stern The stern is the back or aft-most part of a ship or boat, technically defined as the area built up over the sternpost, extending upwards from the counter rail to the taffrail. The stern"
"different sets of designers and for a broad spectrum of uses. Variations on these basic designs have resulted in an outflow of ""new"" stern types and names, only some of which are itemized here. The reverse stern, reverse transom stern, sugar-scoop, or ""retroussé"" stern is a kind of transom stern that is raked backwards (common on modern yachts, rare on vessels before the 20th century); the vertical transom stern or plumb stern is raked neither forward nor back, but falls directly from the taffrail down to the wing transom. The rocket ship stern is a term for an extremely angled"
"""retroussé"" stern. A double ended ship with a very narrow square counter formed from the bulwarks or upper deck above the head of the rudder is said to have a pink stern or pinky stern. The torpedo stern or torpedo-boat stern describes a kind of stern with a low rounded shape that is nearly flat at the waterline, but which then slopes upward in a conical fashion towards the deck (practical for small high-speed power boats with very shallow drafts). A Costanzi stern is a type of stern designed for use on ocean-going vessels. It is a compromise between the"
"Transom (nautical) In naval architecture, a transom is either the surface that forms the stern of a vessel or one of the many horizontal beams that make up that surface (e.g., the ""wing transom"", etc.). Transoms may be flat or curved and they may be vertical, raked forward, also known as a retroussé or reverse transom, angling forward (toward the bow) from the waterline to the deck, or raked aft, often simply called ""raked"", angling in the other direction. The bottom tip of the transom can be approximately on the waterline, in which case the stern of the vessel is"
"Bow (ship) The bow is the forward part of the hull of a ship or boat, the point that is usually most forward when the vessel is underway. Both of the adjectives ""fore"" and ""forward"" mean towards the bow. The other end of the boat is the stern. From Middle Dutch ""boech"" or Old Norse ""bógr"" (shoulder). The bow is designed to reduce the resistance of the hull cutting through water and should be tall enough to prevent water from easily washing over the top of it. On slower ships like tankers, a fuller bow shape is used to maximise"
"when under fire, elliptical sterns still had obvious weaknesses which the next major stern development—the iron-hulled cruiser stern—addressed far better and with much different materials. In naval architecture, the term ""transom"" has two meanings. First, a transom can refer to any of the individual beams that run side-to-side or ""athwart"" the hull at any point abaft the fashion timber; second, a transom can refer specifically to the flat or slightly curved surface that is the very back panel of a transom stern. In this sense, a transom stern is the product of the use of a series of transoms, and"
"Aft Aft, in naval terminology, is an adjective or adverb meaning, ""towards the stern (rear) of the ship"", when the frame of reference is within the ship, headed at the fore. Example: ""Able Seaman Smith; lay aft!"". Or; ""What's happening aft?"" Aft also describes the direction of movement within an aircraft; that is, towards the tail. Example: ""Let's go aft"". Meaning to pull back on the yoke. It may also describe the back/tail location or region within an aircraft cabin. Example: ""Aft lavatory"". The difference between aft and stern is that aft is the ""inside"" (onboard) rearmost part of the"
"Strake A strake is part of the shell of the hull of a boat or ship which, in conjunction with the other strakes, keeps the vessel watertight and afloat. It is a strip of planking in a wooden vessel or of plating in a metal one, running longitudinally along the vessel's side, bottom or the turn of the bilge, usually from one end of the vessel to the other. On a longboat, one strake will typically be made up of numerous planks running end to end. The strake immediately adjacent to the keel is known as the ""garboard strake"". There"
"referred to as a ""transom stern"", or the hull can continue so that the centreline is well above the waterline before terminating in a transom, in which case it is referred to as a ""counter stern"" or ""cutaway stern."" On smaller vessels where an outboard motor is the source of propulsion, the motor is usually mounted on the transom, and held in place either by clamps or metal bolts that go through the transom. In this arrangement, all the power of the motor is transmitted via the transom to the rest of the vessel's structure, making it a critical part"
"another ship in a 1973 collision. The forward part of the bow, usually on the ship's centreline, is called the stem. Traditionally, the stem was an upright timber or metal bar into which side planks or plates were joined. Several types of bows exist. These include: Bow (ship) The bow is the forward part of the hull of a ship or boat, the point that is usually most forward when the vessel is underway. Both of the adjectives ""fore"" and ""forward"" mean towards the bow. The other end of the boat is the stern. From Middle Dutch ""boech"" or Old"
"is the left-hand side and the starboard side is the right-hand side. However, port and starboard never change; they are unambiguous references that are ""not"" based on the relative directions of an observer, just as the cardinal directions of east and west do not change no matter the direction a person faces. The term ""starboard"" derives from the Old English ""steorbord"", meaning the side on which the ship is steered. Before ships had rudders on their centrelines, they were steered with a steering oar at the stern of the ship on the right hand side of the ship, because more"
"Stem (ship) The stem is the most forward part of a boat or ship's bow and is an extension of the keel itself. It is often found on wooden boats or ships, but not exclusively. The stem is the curved edge stretching from the keel below, up to the gunwale of the boat. It is part of the physical structure of a wooden boat or ship that gives it strength at the critical section of the structure, bringing together the port and starboard side planks of the hull. There are two styles of stems: plumb and raked. When the stem"
"counter rail, immediately under the stern's lowest set of windows (which in naval parlance were called ""lights""). The visual unpopularity of Seppings' circular stern was soon rectified by Sir William Symonds. In this revised stern, a set of straight post timbers (also called ""whiskers"", ""horn timbers"", or ""fan tail timbers"") stretches from the keel diagonally aft and upward. It rests on the top of the sternpost and runs on either side of the rudder post (thus creating the ""helm port"" through which the rudder passes) to a point well above the vessel's waterline. Whereas the timbers of the transom stern"
"ship may have its superstructure or aftercastle located in the stern and thus not have an afterdeck. The stern and afterdeck of a ship are usually more smooth and stable than the bow (front) of the ship in motion. A taffrail is the handrail around the open afterdeck or poop deck. On wooden sailing ships like man-of-war or East Indiaman the taffrail is usually a hand carved wood rail and often highly decorated. Afterdeck In naval architecture an afterdeck or after deck or sometimes the aftdeck aft deck or a-deck is the open deck area toward the stern or aft"
"Astern propulsion Astern propulsion (as applied to a ship) is a maneuver in which a ship's propelling mechanism is used to develop thrust in a retrograde direction. Astern propulsion does not necessarily imply the ship is moving astern (""in reverse""); astern propulsion is used to slow a ship by applying a force in the direction of the stern of the ship, instead of the bow. The equivalent concept for an airplane is reverse thrust. In a sailing ship astern propulsion can be achieved by the appropriate manipulation of the sails. In square-rigged ships 'backing the sails', that is, aligning the"
"a vessel in reverse. A ship's stern is flat and lacks the pointed structure of a bow, and a ship is therefore difficult to maneuver in reverse when using the rudder, also found on the stern. The reverse maneuvering was accomplished therefore through shouted instructions from the wharf to the wheelhouse, via intermediary deckhands. Such communication was prone to misunderstanding owing to the wide variety of nationalities employed on United States merchant vessels during the 19th century. Bum steer To give a bum steer is a predominantly Australian, New Zealand and North American idiom that means to provide information, intentionally"
"bottom slamming or shipping of green water occurring in rough seas. The sides are flared to prevent the ship from stopping or being damaged when operating in compressive ice fields. The aft part of the hull, while a compromise between good reversing qualities in the ice and low level of propeller-induced vibrations in the stern, is also designed to prevent pieces of ice from coming in contact with the propeller. The ships are also equipped with stern notches similar to those found in icebreakers, but instead of towing other ships they are meant to be used to allow safe assistance"
"aft, is called right-handed. One that turns anticlockwise is said to be left-handed. Larger vessels often have twin screws to reduce ""heeling torque"", counter-rotating propellers, the starboard screw is usually right-handed and the port left-handed, this is called outward turning. The opposite case is called inward turning. Another possibility is contra-rotating propellers, where two propellers rotate in opposing directions on a single shaft, or on separate shafts on nearly the same axis. Contra-rotating propellers offer increased efficiency by capturing the energy lost in the tangential velocities imparted to the fluid by the forward propeller (known as ""propeller swirl""). The flow"
"a ship. The need for impersonal terms is most clearly seen in a rowing shell where the majority of the crew face aft (""backwards""), hence the oars to their right are actually on the port side of the boat. Rowers eschew the terms left, right, port and starboard in favor of stroke-side and bow-side. The usage derives from the tradition of having the stroke (the rower closest to the stern of the boat) oar on the port side of the boat. Most human cultures use relative directions for reference, but there are exceptions. Australian Aboriginal peoples like the Guugu Yimithirr,"
"boats. The cost of boring out the outer shafts and problems of mounting the inner shaft bearings are not worth pursuing in case of normal ships. Contra-rotating Contra-rotating, also referred to as coaxial contra-rotating, is a technique whereby parts of a mechanism rotate in opposite directions about a common axis, usually to minimise the effect of torque. Examples include some aircraft propellers, resulting in the maximum power of a single piston or turboprop engine to drive two propellers in opposite rotation. Contra-rotating propellers are also common in some marine transmission systems, in particular for large speed boats with planing hulls."
"the stem. Stem (ship) The stem is the most forward part of a boat or ship's bow and is an extension of the keel itself. It is often found on wooden boats or ships, but not exclusively. The stem is the curved edge stretching from the keel below, up to the gunwale of the boat. It is part of the physical structure of a wooden boat or ship that gives it strength at the critical section of the structure, bringing together the port and starboard side planks of the hull. There are two styles of stems: plumb and raked. When"
"Manoeuvring thruster Manoeuvring thruster (bow thruster or stern thruster) is a transversal propulsion device built into, or mounted to, either the bow or stern, of a ship or boat to make it more maneuverable. Bow thrusters make docking easier, since they allow the captain to turn the vessel to port or starboard side, without using the main propulsion mechanism which requires some forward motion for turning; The effectiveness of a thruster is curtailed by any forward motion due to the Coandă effect. A stern thruster is of the same principle, fitted at the stern. Large ships might have multiple bow"
"Aftercastle An aftercastle (or sterncastle, sometimes aftcastle) is the stern structure behind the mizzenmast and above the transom on large sailing ships, such as carracks, caravels, galleons and galleasses. It usually houses the captain's cabin and perhaps additional cabins and is crowned by the poop deck, which on man-of-wars provided a heightened platform from which to fire upon other ships; it was also a place of defence in the event of boarding. More common, but much smaller, is the forecastle. As sailing ships evolved, the aftercastle gave way to the quarterdeck, whose span ran all the way to the main"
"Sterndrive A sterndrive or inboard/outboard drive (I/O) is a form of marine propulsion which combines inboard power with outboard drive. The engine sits just forward of the transom while the drive unit (outdrive or drive leg) lies outside the hull. The drive unit (outdrive) carries power from the inboard engine, typically mounted above the waterline, outboard through the transom and downward to the propeller below the waterline. The outdrive resembles the bottom half of an outboard motor and is composed of two sub-units: an upper containing a driveshaft connected through the transom to an engine which transmits power to a"
"Backstay A backstay is a piece of standing rigging on a sailing vessel that runs from the mast to either its transom or rear quarter, counteracting the forestay and jib. It is an important sail trim control and has a direct effect on the shape of the mainsail and the headsail. Backstays are generally adjusted by block and tackle, hydraulic adjusters, or lines leading to winches. Backstays may be ""permanent"" or ""running"". A permanent backstay is attached to the top of the mast. Running backstays appear in pairs attached about two-thirds of the way up the mast (sometimes at multiple"
"Skeg A skeg, (skegg or skag) is a sternward extension of the keel of boats and ships which have a rudder mounted on the centre line. The term also applies to the lowest point on an outboard motor or the outdrive of an inboard/outboard. In more recent years, the name has been used for a fin on a surfboard which improves directional stability and to a movable fin on a kayak which adjusts the boat's centre of lateral resistance (it moves the center of resistance relative to the center of effort). The term is also often used for the fin"
"have any number of masts provided the second from the front is the tallest (called the ""main mast""). In both a ketch and a yawl, the foremost mast is tallest, and thus the main mast, while the rear mast is shorter, and called the mizzen mast. The difference between a ketch and a yawl is that in a ketch, the mizzen mast is forward of the rudderpost (the axis of rotation for the rudder), while a yawl has its mizzen mast behind the rudderpost. In modern parlance, a brigantine is a vessel whose forward mast is rigged with square sails,"
"deck. The stern now came to a point rather than a flat panel or a gentle curve, and the counter reached from the sternpost all the way to the taffrail in a continuous arch. It was soon discovered that vessels with cruiser sterns experienced less water resistance when under way than those with elliptical sterns, and between World War I and World War II most merchant ship designs soon followed suit. None of these three main types of stern has vanished from the modern naval architectural repertoire, and all three continue to be utilized in one form or another by"
"vessel's starboard side by green and its port side by red. Aircraft are lit in the same way. Port and starboard Port and starboard are nautical and aeronautical terms of orientation that deal unambiguously with the structure of vessels and aircraft. Their structures are largely bilaterally symmetrical, meaning they have mirror-image left and right halves if divided long-ways down the middle. One asymmetric feature is that on aircraft and ships where access is at the side, this access is usually only provided on the port side. To understand which is which, when a person is facing the bow on a"
"or keel/centerboard --- a non-trivial venture. Traditionally there are two stations on the bridge of a sea going ship for controlling the vessel's maneuvers: the Helm, which uses a wheel (or touchscreen equivalent) to send signals to control the position of the rudder or rudders, and the Lee Helm, which traditionally inputs speed commands by operating an engine order telegraph that sends engine commands to the engineering personnel below decks. On modern US Navy surface vessels that use gas turbine or diesel propulsion, the lee helm actually directly controls the ship's speed via throttle control (either a manual throttle lever"
"mast. Aftercastle An aftercastle (or sterncastle, sometimes aftcastle) is the stern structure behind the mizzenmast and above the transom on large sailing ships, such as carracks, caravels, galleons and galleasses. It usually houses the captain's cabin and perhaps additional cabins and is crowned by the poop deck, which on man-of-wars provided a heightened platform from which to fire upon other ships; it was also a place of defence in the event of boarding. More common, but much smaller, is the forecastle. As sailing ships evolved, the aftercastle gave way to the quarterdeck, whose span ran all the way to the"