Yacht

thumb|A 45-foot cruising yacht in 2010

thumb|The [[superyacht Azzam, the longest private yacht, as of 2018. There is no standard definition, though the term generally applies to vessels with a cabin intended for overnight use.

The Commercial Yacht Code classifies yachts and over as . Such yachts typically require a hired crew and have higher construction standards.

Racing yachts are designed to emphasize performance over comfort. Charter yachts are run as a business for profit.

History

The history of pleasure boats begins with rowed craft in Pharaonic Egyptian times, and other vessels in the waters of Myanmar, India, Mindanao and Japan. Anglo-Saxon royal pleg-scips (play ships) of the 8th-century featured ornamented bows and sterns and had the capability of cooking on board.

Sail

thumb|1893 [[America's Cup match between Vigilant and Valkyrie II]]

The history of sailing yachts begins in Europe in the beginning of the 1600s with the building of a pleasure vessel for the son of King James I of England. While other monarchs used naval ships for transportation and conquest, James I was the first English monarch to commission the construction of a yacht—for his son Henry, Prince of Wales in the early 1600s. Pleasure vessels acquired the name yacht after the time of Charles II, who spent time exiled in Europe and visited the Netherlands, where a variety of jachten were already well developed as pleasure boats for the elite classes since the beginning of the 17th century. Upon his restoration to the English crown, Charles was presented with a yacht and later commissioned a series of royal yachts, which included at least one experimental catamaran. The first recorded yacht race between two vessels occurred in 1661, followed by the first open sailing competition in 1663 in English waters.

Starting in 1739, England found itself in a series of wars—a period that saw a decline in yachting. In Ireland, however, the gentry enjoyed yachting and founded the first yacht club in Cork as the Cork Harbour Water Club in 1720. English yacht racing continued among the English gentry who founded England's oldest yacht club, the Cumberland Fleet, in 1775. With maritime peace, starting in 1815, came a resurgence of interest in yachting. Boatbuilders, who had been making fast vessels both for smugglers and the government revenue cutters, turned their skills again to yachts.

Power

thumb|Steam yacht, [[Gunilda, ]]

thumb|Turkish state yacht, [[Savarona in 2014, a steam-turbine yacht re-engined with diesels]]

While sailing yachts continued to exist, the development of reliable power plants created a new category of pleasure craft. The power plants started with the steam engine and transitioned to the internal combustion engine. Whereas sailing yachts continued to be steered from the after portion of the vessel, power yachts adopted the bridge in a forward cabin structure that afforded better forward and sideways visibility. Steam yachts evolved with the development of the steam engine. Ultimately, engines employed pistons driven by steam within cylinders, connected to a crank shaft, which drove a propeller. Steam engines remained the dominant source of power until the early 20th century, when advances in the design of the steam turbine, electric motors and internal combustion engines gradually resulted in the replacement of reciprocating (piston) steam engines.

Large steam yachts were luxurious; their staff included a captain, engineer, and stewards, as well as deck hands. Diesel power plants for boats were demonstrated in 1903. Diesels became a more prevalent type of power plant in the 20th century thanks to their low cost of operation and reliability.

yachts are fit for conditions that exceed wind force 8——and maximum wave heights, encountered in ocean passages and extended voyages.
yachts are fit for conditions that are less than wind force 8——and maximum wave heights, encountered in ocean passages and extended voyages.
yachts are fit for wind force 6——and maximum wave heights, encountered in exposed coastal waters, bays inlets, lakes and rivers.
yachts are fit for wind force 4——and maximum wave heights, encountered in sheltered coastal waters, bays inlets, lakes and rivers.

The of Great Britain and its dominions defines a as one that is or more at the waterline and is in commercial use for sport or pleasure, while not carrying cargo or more than 12 passengers and carrying a professional crew. The code regulates the equipping of such vessels, both at sea and in port—including such matters as crew duty times and the presence of a helicopter on board. The code has different levels of standard for vessels above and below 500 gross tons. Such yachts may be considered and are more commonly at or more in length. Other countries have standards similar to LY2.

Whereas large yachts may carry no more than 12 passengers, yachts are solely for the pleasure of the owner and guests do not carry the passenger restriction. Yachts may be identified by flag—the country under which a yacht is registered. by speed, as "explorer" yachts, as sailing yachts, and as classic yachts.

Construction

Originally, all yachts were made of wood, using a wooden keel and ribs, clad with planks. These materials were supplanted with iron or steel in steam yachts. Whereas yachts of and below may be constructed of fiberglass, larger yachts are more likely to be constructed of steel, aluminum or composite fiber-reinforced plastic.

Wood construction, using conventional planks over ribs continues. Hard-chined boats made with plywood is an infrequent technique, whereas yachts made with the WEST system—plies of wood strips, soaked in epoxy and applied over the boat frame—provide a durable, lightweight and robust hull.
Metal hulls from steel or aluminum offer the opportunity for welding components to a completely watertight hull. Both metals are vulnerable to damage due to electrolysis. Steel is easy to repair in boatyards around the world, whereas aluminum is a much lighter material.
Fiberglass construction is best suited for mass-produced yachts, using a mold and is therefore the most prevalent material. Fiberglass skins comprise plies of roving (glass fabric) and matting, soaked in resin for the hull. Decks typically have a core of balsa, or PVC foam between layers of glass mat. Both elements of construction are vulnerable to intrusion of water and the development of blisters below the waterline.

Transport

thumb|M/V Yacht Servant, with a cargo of yachts, is a purpose-built semi-submersible vessel.

As an alternative to the traditional passaging (sailing or motoring), yachts can also be shipped, usually when the destination and cruising is more important than the passaging, as it generally eliminates costly and time-consuming ocean crossings.

Trailers, whether private or commercial, are often used to transport small yachts for short distances. As the yacht size and the over-land distances increase, yacht owners typically employ commercial trailer services to move vessels.

thumb|Semi-submersible ship DYT Yacht Express at Port Everglades, Fort Lauderdale, Florida, USA.

Yacht owners sometimes employ semi-submersible ships to relocate their craft to distant cruising grounds. Such ships submerge sufficiently to allow a yacht to be floated on or off a pre-prepared cradle, which shall be certified for marine transport by one of the IACS member , and then re-float, lifting the yacht out of the water for transport. These ships travel among North American, Caribbean, and Pacific-Ocean destinations.

thumb|M/V Statengracht, with a cargo of yachts in the port of West Palm Beach, Florida.

Yachts can be shipped as deck and/or underdeck cargo mostly on Heavy-lift ships or Multi-purpose vessels and that is mostly limited to those equipped with their own cranes, which makes a transport less costly comparing to options requiring usage of shore or floating cranes but opens up geographical that have no shore or floating cranes available, and allows the loading and discharging at the protected anchorages without using costly port infrastructure.

Yachts are also transported by container ships, arranged through freight forwarders. Container shipment costs are almost independent of distance shipped and depend more on imbalances in container locations. It is significantly less expensive and has greater flexibility with respect to timing and destinations. The drawback to container cruising is that there are a limited number of yachts that have the necessary sizes that fit in a standard container.

Accommodations

thumb|Sailing yacht interior with fold-down table in main salon, galley (kitchen) on left, and navigation station on right and forward cabin visible beyond.

Depending on size, a cruising yacht is likely to have at least two cabins, a main salon and a forward stateroom. In smaller yachts, the salon is likely to have convertible berths for its crew or passengers. Typically the salon includes a dining area, which may have a folding, built-in table. The salon is typically contiguous to the galley. A cruising yacht is likely to have a head (bathroom) with a marine toilet that discharges waste into a holding tank. Larger yachts may have additional staterooms and heads. There is typically a navigation station that allows planning the route.

Systems

thumb|Wheelhouse of motor yacht, [[Taransay (yacht)|Taransay, in 2015 with navigation and systems displays]]

Onboard systems include:

Communications equipment includes radios in a variety of bandwidths, specifically for maritime use.
Instrumentation also provides information on depth of water under the vessel (depth sounder), windspeed (anemometer), and directional orientation (compass).
Navigation electronics include units that identify a vessel's location (e.g. GPS) and display the vessel's location (chartplotter) and other vessels and nearby shore (radar).

Sailing yachts

thumb|Small sailing yacht with [[outboard motor in 2017]]

Sailing yachts for cruising versus racing embody different tradeoffs between comfort and performance. Cruising yachts emphasize comfort over performance. Racing yachts are designed to compete against others in their class, while providing adequate comfort to their crews.

Cruising

Cruising yachts may be designed for near-shore use or for passage-making. They may also be raced, but they are designed and built with the comfort and amenities necessary for overnight voyages. Qualities considered in cruising yachts include: performance, comfort under way, ease of handling, stability, living comfort, durability, ease of maintenance, affordability of ownership.

Rigs

Gaff rigs have been uncommon in the construction of cruising boats, since the mid 20th century. More common rigs are Bermuda, fractional, cutter, and ketch. Occasionally employed rigs since then have been the yawl, schooner, wishbone, catboat. whereas a sailboat might have a engine.

Racing

thumb|Racing yacht, Comanche, beginning a 2015 transatlantic race

Racing yachts emphasize performance over comfort. World Sailing recognizes eleven classes of racing yacht.

Design features

High-performance rigs provide aerodynamic efficiency and hydrodynamically efficient hulls minimize drag through the water and sideways motion.

Racing yachts have a wide selection of weights and shapes of sail to accommodate different wind strengths and points of sail. A suite of sails on a racing yachts would include several weights of jib and spinnaker, plus a specialized storm jib and trysail (in place of the mainsail). Performance yachts are likely to have full-battened kevlar or carbon-fiber mainsails. On some racing yachts, a canting keel shifts angle from side to side to promote sailing with less heeling angle (sideway tilt), while other underwater foils take care of leeway (sideways motion). which when launched would replace the Azzam as the longest superyacht.

Class A: motorboats less than
Class 1: motorboats
Class 2: motorboats
Class 3: motorboats

Style

A motor yacht's style can both be functional and evoke an aesthetic—trending towards the modern or the traditional. Among the styles, mentioned in the literature, are:

Cruiser – A cruiser has a displacement hull for economical, long-distance passage-making.
Sports cruiser – A sports cruiser has a semi-displacement or planing hull for fast trips.
Sports fisherman – A sports fisherman has a semi-displacement or planing hull for fast trips and carries gear for recreational catching of large fish.
Expedition – An expedition yacht has a displacement hull for economical, long-distance passage-making to remote destinations. These are also called yachts.

Full-displacement hulls move the water up and out of the way of the vessel, making a wave. They are limited in speed by the square root of the waterline length multiplied by a factor, depending on the units used. Added horsepower cannot increase the maximum speed, only the size of the waves produced.
Semi-displacement hulls allow speeds that are faster than the hull speed of a displacement vessel because they rise somewhat out of the water and create smaller waves. They also provide greater comfort than planing hulls.
Planing hulls require sufficient power for the boat to plane on the surface, which avoids the need to use power to lift water out of the way of the vessel. Such vessels have flat surfaces on the undersides.

A typical semi-displacement yacht has a wedge-shaped bow, which promotes penetrating waves, that transitions to flatter, wider surfaces aft, which promotes lifting the vessel out of the water—the "deep vee" hull, designed by Ray Hunt, found in approximately 75% of modern power boats.

Cruising motor yachts are available in a range of styles as two-engine , ranging in length from with top speeds ranging from .

Engines

thumb| diesel [[Inboard motor|marine engine]]

Motor yachts typically have one or more diesel engines. Gasoline-powered motors and engines are the provenance of outboard motors and racing boats, due to their power-to-weight ratios.

Motor yachts in the range might have the following hull, horsepower, cruise speed, and hourly fuel consumption characteristics:

– two diesels to cruise at , consuming .
– two diesels to cruise at , consuming .
– two diesels to cruise at , consuming . or a combination of diesels and gas turbines with a combined .

References