#### DuneCraig

##### New member

Does anybody know the calculation of the potential speed of a yacht?

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- Thread starter DuneCraig
- Start date

Does anybody know the calculation of the potential speed of a yacht?

1.4 multiplied by the square root of the length at the waterline

My boat has a waterline length of about 28 feet, which even at a factor of 1.5 means I should not exceed 8 knots, but I know my boat actually seems to top out at 8.9 knots (often measured where no tide is running and confirmed by GPS).

Anyone able to explain?

regards olewill

As with cars the easiest way to make your boat go faster is to retune your speedo.

An Online calculator using 1.34 factor.

It also seems to me that the actual displacement must have an effect, after all, the bow wave is, I assume, created by the water the boat displaces, the more the displacement presumably the bigger the bow wave at a given speed, so the quicker you would reach hull speed. Would that be correct?

Was Froude actually looking at yachts and their sort of shape, or was he working on designs for ships?

regards olewill