using a tape measure is the best way and the preferred method according th o the US Navy.
The overall length of a pleasure craft is measured from the tip of the bow (front) to the stern (back) at the longest point of the vessel, including any extensions like swim platforms or bowsprits. This measurement should be taken along the centerline of the boat. It's important to ensure that the boat is on a level surface for an accurate measurement. Always refer to the manufacturer's specifications for guidance if available.
yard
from the base to the tip.
A 21 foot boat refers to the length of the boat. There is not comparison between length and width. It could be narrow as on narrow boats or wide as in sea faring boats,
A D/L ratio is calculated by dividing a boat's displacement in long tons (2,240 pounds) by one one-hundredth of the waterline length (in feet) cubed.
use a metre stick
using a tape measure is the best way and the preferred method according th o the US Navy.
There are varied "correct" answers to this question, as many separate entities identify different meanings. Generally Length Overall (LOA) is a measurement taken along the hull, parallel to the waterline. In some instances it can also include the bowsprite to the fantail.
The overall length of a pleasure craft is measured from the tip of the bow (front) to the stern (back) at the longest point of the vessel, including any extensions like swim platforms or bowsprits. This measurement should be taken along the centerline of the boat. It's important to ensure that the boat is on a level surface for an accurate measurement. Always refer to the manufacturer's specifications for guidance if available.
yard
from the base to the tip.
That depends what you want to measure - its length, its mass, its color, etc.
A boat's length overall dictates the equipment the boat must have to comply with federal and state laws.
A web reference states "The beam of many monohulls can be calculated by using the following formula."Beam=LOA(Length overall) in feet to the power of 2/3 +1Hope this helps.
To calculate the linear square footage of a boat, you would measure the length of the boat in feet and multiply it by the average beam (width) of the boat in feet. This will give you the total square footage of the boat's surface area. Keep in mind that this calculation assumes the boat's hull has a rectangular shape, so it may not be entirely accurate for boats with irregular shapes.
You can do so in any unit but in backward countries people talk of boat lengths in feet because they use the imperial system. More properly they should use the international standard unit of length which which the meter and would be understood worldwide.
The length of a motor boat is not restricted