A hydrofoil is a lifting surface, or foil, that operates in water. They are similar in appearance and purpose to aerofoils used by aeroplanes. Boats that use hydrofoil technology are also simply termed hydrofoils. As a hydrofoil craft gains speed, the hydrofoils lift the boat's hull out of the water, decreasing drag and allowing greater speeds.
A 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, and trimarans. There are other types, with four or more hulls, but such examples are very rare and tend to be specialised for particular functions.
A yacht is a sailing or power vessel used for pleasure, cruising, or racing. There is no standard definition, though the term generally applies to vessels with a cabin intended for overnight use. To be termed a yacht, as opposed to a boat, such a pleasure vessel is likely to be at least 33 feet (10 m) in length and may have been judged to have good aesthetic qualities.
Naval architecture, or naval engineering, is an engineering discipline incorporating elements of mechanical, electrical, electronic, software and safety engineering as applied to the engineering design process, shipbuilding, maintenance, and operation of marine vessels and structures. Naval architecture involves basic and applied research, design, development, design evaluation (classification) and calculations during all stages of the life of a marine vehicle. Preliminary design of the vessel, its detailed design, construction, trials, operation and maintenance, launching and dry-docking are the main activities involved. Ship design calculations are also required for ships being modified. Naval architecture also involves formulation of safety regulations and damage-control rules and the approval and certification of ship designs to meet statutory and non-statutory requirements.
A catamaran is a watercraft with two parallel hulls of equal size. The distance between a catamaran's hulls imparts resistance to rolling and overturning. Catamarans typically have less hull volume, smaller displacement, and shallower draft (draught) than monohulls of comparable length. The two hulls combined also often have a smaller hydrodynamic resistance than comparable monohulls, requiring less propulsive power from either sails or motors. The catamaran's wider stance on the water can reduce both heeling and wave-induced motion, as compared with a monohull, and can give reduced wakes.
A trimaran is a multihull boat that comprises a main hull and two smaller outrigger hulls which are attached to the main hull with lateral beams. Most modern trimarans are sailing yachts designed for recreation or racing; others are ferries or warships. They originated from the traditional double-outrigger hulls of the Austronesian cultures of Maritime Southeast Asia; particularly in the Philippines and Eastern Indonesia, where it remains the dominant hull design of traditional fishing boats. Double-outriggers are derived from the older catamaran and single-outrigger boat designs.
Skjold-class corvettes are a class of six light, superfast, stealth missile corvettes in service with the Royal Norwegian Navy. The boats were formerly classed as MTBs but, from 2009, the Royal Norwegian Navy has described them as corvettes (korvett) because their seaworthiness is seen as comparable to corvettes, and because they do not carry torpedoes. They were built at the Umoe Mandal yard. With a maximum speed of 55 knots (102 km/h), the Skjold-class corvettes were the fastest combat ships afloat at the time of their introduction.
Proas are various types of multi-hull outrigger sailboats of the Austronesian peoples. The terms were used for native Austronesian ships in European records during the Colonial era indiscriminately, and thus can confusingly refer to the double-ended single-outrigger boats of Oceania, the double-outrigger boats of Island Southeast Asia, and sometimes ships with no outriggers or sails at all.
A small waterplane area twin hull, better known by the acronym SWATH, is a catamaran design that minimizes hull cross section area at the sea's surface. Minimizing the ship's volume near the surface area of the sea, where wave energy is located, minimizes a vessel's response to sea state, even in high seas and at high speeds. The bulk of the displacement necessary to keep the ship afloat is located beneath the waves, where it is less affected by wave action. Wave excitation drops exponentially as depth increases, so wave action normally does not affect a submerged submarine at all. Placing the majority of a ship's displacement under the waves is similar in concept to creating a ship that rides atop twin submarines.
Capsizing or keeling over occurs when a boat or ship is rolled on its side or further by wave action, instability or wind force beyond the angle of positive static stability or it is upside down in the water. The act of recovering a vessel from a capsize is called righting. Capsize may result from broaching, knockdown, loss of stability due to cargo shifting or flooding, or in high speed boats, from turning too fast.
Incat Tasmania is an Australian manufacturer of high-speed craft (HSC) catamaran ferries. Its greatest success has been with large, sea going passenger and vehicle ferries, but it has also built military transports and since 2015 it has built smaller river and bay ferries. Based in Derwent Park, a suburb of Hobart, Tasmania, Australia, it was founded by Bob Clifford.
Hull speed or displacement speed is the speed at which the wavelength of a vessel's bow wave is equal to the waterline length of the vessel. As boat speed increases from rest, the wavelength of the bow wave increases, and usually its crest-to-trough dimension (height) increases as well. When hull speed is exceeded, a vessel in displacement mode will appear to be climbing up the back of its bow wave.
A stealth ship is a ship that employs stealth technology construction techniques in an effort to make it harder to detect by one or more of radar, visual, sonar, and infrared methods.
Hobie Cat is a company that manufactures sailing catamarans, surfboards, sailboats, kayaks, stand-up paddle boards, and pedalboards as the Hobie Cat Company. It was founded in 1961 by Hobart Alter, who originally manufactured surfboards. Its line of products has included more than twenty sailing craft, plus a variety of other watercraft.
The Type 22 missile boat is a ship class in the Chinese People's Liberation Army Navy. The first boat was launched in April 2004 by the Hudong-Zhonghua Shipyard at Shanghai. The boats incorporate stealth features and are based on Australian-designed wave-piercing catamaran hulls that are more stable than other fast missile craft in high sea conditions. 82 of these missile boats are currently in service with three flotillas having been produced over a span of seven years, operating in squadrons of eight vessels each.
A sailing yacht, is a leisure craft that uses sails as its primary means of propulsion. A yacht may be a sail or power vessel used for pleasure, cruising, or racing. There is no standard definition, so the term applies here to sailing vessels that have a cabin with amenities that accommodate overnight use. To be termed a "yacht", as opposed to a "boat", such a vessel is likely to be at least 33 feet (10 m) in length and have been judged to have good aesthetic qualities. Sailboats that do not accommodate overnight use or are smaller than 30 feet (9.1 m) are not universally called yachts. Sailing yachts in excess of 130 feet (40 m) are generally considered to be superyachts.
In ship design, an inverted bow is a ship's or large boat's bow whose farthest forward point is not at the top. The result may somewhat resemble a submarine's bow. Inverted bows maximize the length of waterline and hence the hull speed, and have often better hydrodynamic drag than ordinary bows. On the other hand, they have very little reserve buoyancy and tend to dive under waves instead of piercing or going over them.
LOMOcean Marine is a naval architecture and yacht design company based in Auckland, New Zealand.
The Klewang-class fast attack craft is a stealth, wave-piercing, carbon trimaran fast attack craft built by PT Lundin Industry Invest and designed by LOMOcean Marine. Shortly after being floated out, on 28 September 2012, KRI Klewang was destroyed by fire while being outfitted at shipyard. The second ship in the class KRI Golok was launched on 21 August 2021.
