The displacement–length ratio (DLR or D/L ratio) is a calculation used to express how heavy a
boat
A boat is a watercraft of a large range of types and sizes, but generally smaller than a ship, which is distinguished by its larger size or capacity, its shape, or its ability to carry boats.
Small boats are typically used on inland waterways s ...
is relative to its
waterline length.
DLR was first published in
It is calculated by dividing a boat's
displacement
Displacement may refer to:
Physical sciences
Mathematics and physics
*Displacement (geometry), is the difference between the final and initial position of a point trajectory (for instance, the center of mass of a moving object). The actual path ...
in
long ton
The long ton, also known as the imperial ton, displacement ton,Dictionary.com - ''"a unit for measuring the displacement of a vessel, equal to a long ton of 2240 pounds (about 1016 kg) or 35 cu. ft. (1 cu. m) of seawater."'' or British ton, is a ...
s (2,240 pounds) by the cube of one one-hundredth of the waterline length (in feet):
:
DLR can be used to compare the relative mass of various boats no matter what their length. A DLR less than 200 is indicative of a racing boat, while a DLR greater than 300 or so is indicative of a heavy cruising boat.
See also
*
Sail Area-Displacement ratio
References
Ship measurements
Nautical terminology
Engineering ratios
Naval architecture
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