Merci Jean paul

J’en ai retenu ceci

It is also possible to compute boat polar from an augmented sailboat transform calculation. The original sailboat transform :

2
/ sin(A/2) \
sin(W) sin(A) | ---------- | = VW eta
\ sin(W - A) /

W is true wind angle
A is apparent Wind angle
VW is true wind speed
eta is a boat specific constant specifying it’s sailing efficiency.