# How to use a SAC(section Area Coefficient) to calculate wsa?

Discussion in 'Boat Design' started by JorgenBeyer, Nov 25, 2009.

1. Joined: Jan 2008
Posts: 17
Likes: 3, Points: 0, Legacy Rep: 9
Location: Southampton

### JorgenBeyerJorgenBeyer

Hello.

I have now done lots of research but i am unable to figure out how to calculate my keels wetted surface area. for the keel i have the root chord, the tip chord, its span, its thickness/chord ratio and the sac. i assume you must use Simpson's rule but i can't figure out how. can anyone help me asap?

root and tip chord = 1,2 m
Span = 0,975 m
T/C = 7,5%
SAC = 0,66

2. Joined: Apr 2006
Posts: 60
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Location: Maine

### GreybarnJunior Member

Planform area=span x (root chord + tip chord)/2
Wetted surface area= 2 x planform area + (sectional area at tip)

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