Calculation of power requirement for a boat


#1

How to calculate the minimum power required to drive a vessel of 6 tons?


#2

How long is a piece of string?

Displacement hull? Semi-displacement? Planing? Length? Beam?

How fast for how far? Weather? Currents?

Six tons as in 12,000 pounds?

There are many online calculators available to give you a ballpark number. Another way is to look at similar boats and see what engines they use … most are way overpowered beyond whatever the calculated minimum is because of operational or marketing reasons.

A minimally powered boat is not something you want to own. Do you want to drive a 20 horsepower car?


#3

which type sail board is better for drive a vessel weighing more than 6 tons? How the power calculated when we use more than one outboards?


#4

The information provided by you is very sketchy indeed, except tonnage (which one?) no boat dimensions, nothing. However, for a very crude estimation of the power required for certain speeds I refer to the picture below. Hope this helps.


#5

Some of these posters are like seagulls, they come flying in screeching like what, shit around a bit and are suddenly gone again…


#6

Always torn between f-off troll and taking the poster at his word he really is trying to learn something.
Anyway that formula actually is pretty close for my boat.


#7

Just curious, is the result more accurate with C = 38?