Boat Speed

From 4LPH41337.com

Doing some research on boat speed. There are several factors on boat speed, I've pulled out a few from this site that has WAY more detail: The Shape of the Canoe

1 Hull Speed
2 Displacement/Length Ratio
3 Residual Resistance
4 Longitudinal Coefficient
5 Frictional Resistance

[edit]

Hull Speed

Theoretical top speed of a boat (not absolute)

Hull Speed ~= 1.34 * (squareroot of LWL)

where: "LWL" is the length of the boat at the waterline in feet, and hull speed is the speed of the boat in knots

[edit]

Displacement/Length Ratio

Simply put, if boats weigh the same (assuming same materials and basic shape), the longer boat will be faster.
Displacement = weight
The smaller the number the faster the boat.

Weight/Length

[edit]

Residual Resistance

This is the pushing of water against the bow of the boat, and the sucking of water behind the stern.
The higher the ratio between the length of the boat at the waterline and the beam (width) of the boat, the less residual resistance.
A boat with an 11:1 ratio can travel at speeds close to twice their hull speed.

L/B

[edit]

Longitudinal Coefficient

Asymmetric hulls (fatter in the back) make the boat "appear" longer to the water and is thus faster than a symmetrical boat of the same length at speeds above speed/length of 1.2. However, an asymmetrical boat will have more resistance at low speeds.

[edit]