Mariquita Book - mk2

QUARTER
WAKE
Technical Note
Mariquita has a displacement hull with a relatively blunt ‘spoon’ bow. With a weight of 80 tonnes she
therefore displaces 80 tonnes of water. In order to move forward one hull length, Mariquita must move
80 tonnes of water out of her way, so she can occupy the space where the water has been. In turn the
water flows around the hull to occupy the space where Mariquita has been. Due to the physics of hull
form and wave making, a displacement hull has a limiting speed or terminal velocity. This is a function
of length and is known as waterline length speed. Mariquita’s maximum hull speed is around 12.5
knots. Modern yachts with their light-weight planing hulls are not restricted in this way and therefore
go faster. When Mariquita is doing a maximum hull speed of 12.5 knots she travels one hull length
every five seconds and is thus moving 80 tonnes of water every five seconds – 16 tonnes of water every
second. Although a rough approximation you can begin to appreciate the enormous power generated
by classic yachts such as Mariquita.
David Bedford
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