# Helpful Calculations

- Maximum thickness of a foil is equal to the maximum thickness of the core plus twice the thickness of the skin.
- The chord length of the foil is equal to the chord length of the core plus the thickness of the skin plus the taper of the skin beyond the core (designated by '?' below).

- Center of Gravity of seated crew is 6" inside gunwales
- C of G of hiking crew is 25% of crew's height outside of gunwales
- C of G of trapezing crew is 50% of crew's height outside of gunwales.

### Sample Coefficients of Lift

These are to be used only as general guidelines - coefficient of lift varies according to aspect ratio (and other planform factors) and Reynolds number, to name just some of the variables.C _{L} |
Description |

1.50 | NACA0012 at angle of attack of 15 degrees (max before it stalls) |

0.25 | NACA0012 at angle of attack of 3 degrees (typical leeway angle upwind) |

0.80 | NACA0009 at angle of attack of 10 degrees (max before it stalls) |

0.30 | NACA0009 at angle of attack of 3 degrees |