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LOA (length overall) & LWL (length at the waterline)Detailed hull dimensions
A vessel's length at the waterline (abbreviated to L.W.L)[1] is the length of a ship or boat at the level where it sits in the water (the waterline). The LWL will be shorter than the length of the boat overall (length overall or LOA) as most boats have bows and stern protrusions that make the LOA greater than the LWL. As a ship becomes more loaded, it will sit lower in the water and its ambient waterline length may change; but the registered L.W.L is measured from a default load condition.
This measure is significant in determining several of a vessel's properties, such as how much water it displaces, where the bow and stern waves occur, hull speed, amount of bottom-paint needed, etc. Traditionally, a stripe called the "boot top" is painted around the hull just above the waterline.
In sailing boats, longer waterline length will usually enable a greater maximum speed, because it allows greater sail area,[citation needed] without increasing beam or draft. Greater beam and draft produces a larger wetted surface, thereby causing higher hull drag. In particular, any "displacement" or non-planing boat requires much greater power to accelerate beyond its hull speed, which is determined by the length of the waterline, and can be calculated using the formula: Vmax (in knots) = square root of LWL (in feet) x 1.34. The hull speed is the speed at which the wavelength of the bow wave stretches out to the length of the waterline, thus dropping the boat into a hollow between the two waves. While small boats like canoes can overcome this effect fairly easily, heavier sailboats cannot.
Since waterline length provides a practical limit for the speed of a typical sailboat, traditional rules for racing sailboats often classed boats using waterline length as a principal measure. To get around this rule, designers in the early 20th century began building racing sailboats with long overhangs fore and aft. This resulted in a nominally shorter waterline, but when the boats were sailed they heeled over, pulling the sides of the overhangs into the water as well and creating a much longer effective waterline, and thereby achieving much greater speed. The first recorded use of a line (documented by New Jersey marine museum) is by the small and rather unknown naval fleet of Thomas Jefferson.
vessel's length at the waterline (abbreviated to L.W.L) is the length of a ship or boat at the level where it sits in the water (the waterline). The LWL...
speed is defined by, among other things, the waterlinelength. In a sailing boat, the waterlinelength can change significantly as the boat heels, and...
Length overall (LOA, o/a, o.a. or oa) is the maximum length of a vessel's hull measured parallel to the waterline. This length is important while docking...
speed at which the wavelength of a vessel's bow wave is equal to the waterlinelength of the vessel. As boat speed increases from rest, the wavelength of...
effective when used on vessels that meet the following conditions: The waterlinelength is longer than about 15 metres (49 ft). The bulb design is optimised...
The scantling length refers to the structural length of a ship. Scantling Length is a distance slightly less than the waterlinelength of a ship, and...
or waterlinelength are other common measures of ship length). General Year: launch/delivery/active Shipyard: makers of the yacht LOA: overall length LOD:...
{\displaystyle {\text{speed–length ratio}}={\frac {u}{\sqrt {\text{LWL}}}}} where: u = flow speed LWL = length of waterline The term was converted into...
races to embrace any sailing vessel with more than 30 ft (9.14 m) waterlinelength and on which at least half the people on board are aged 15 to 25. In...
encountered. Performance hinges on a number of factors, including the waterlinelength (longer means faster), drag in the water (narrower hull with smooth...
1972 and was designed by Frank Butler. It has a length overall of 29.92 ft (9.1 m), a waterlinelength of 25.00 ft (7.6 m), displaces 10,200 lb (4,627 kg)...
introduced in 1986 and produced until 1989. The length overall is 25.83 ft (7.87 m), the waterlinelength is 23.50 ft (7.16 m), displaces 2,850 lb (1,293 kg)...
22 This model was introduced in 1969. It has a length overall of 21.50 ft (6.6 m), a waterlinelength of 19.33 ft (5.9 m), displaces 2,490 lb (1,129 kg)...
best possible speed for the length of waterline. Length was between 27 and 31 feet. Beam was just over a fifth of the length. Typically they were propelled...
The Dutch Waterline (Dutch: Hollandsche Waterlinie, modern spelling: Hollandse Waterlinie) was a series of water-based defences conceived by Maurice of...
tons light 12,139 tons full 1,569 tons dead Length 138 m (452.8 ft) overall 128.5 m (421.6 ft) waterlinelength Beam 12.1 m (39.7 ft) Draft 10.9 m (35.8 ft)...
which can mean: Living with ley Lifewide learning Load WaterlineLength / Length at waterline La wea loca This disambiguation page lists articles associated...
examples completed. It has a masthead sloop rig, a length overall of 27.17 ft (8.3 m), a waterlinelength of 22.00 ft (6.7 m), displaces 7,000 lb (3,175 kg)...
40 This model was introduced in 2007. It has a length overall of 39.83 ft (12.1 m), a waterlinelength of 33.92 ft (10.3 m), displaces 18,210 lb (8,260 kg)...
FnV applies when the waterlinelength is too speed-dependent to be meaningful—as with a planing hull. It uses a reference length, the cubic root of the...
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