Yaw angle

[Andrea-]

Ciao Rob, grazie.
Copio il passaggio in questione:
"Like all sailboats working to windward, Agile Angel doesn't actually move ahead in a straight line. Instead, she crabs forward just a bit sideways, or at a slight angle called "yaw angle". In other words, her bow is pointing a bit higher (closer to the wind) than Agile Angel is actually travelling.
This sounds like a waste, but in fact is beneficial. Because of this yaw angle, the keel's not slicing straight forward but is being driven ahead at a slightly oblique angle to the water. The result is that the symmetrical keel presents an asymmetrical shape to the onrushing water. (Yaw angle is, in fact, the "angle of attack"; without it you couldn't have lift at all).

Quello che non mi è chiaro è intanto come si chiama questo Yaw angle in italiano, poi: se è un angolo tra la superficie ipoteticamente piana del mare e l'asse verticale della barca, mi torna: "In other words, her bow is pointing a bit higher (closer to the wind) than Agile Angel is actually travelling." ma non mi torna invece:"Because of this yaw angle, the keel's not slicing straight forward but is being driven ahead at a slightly oblique angle to the water." e neanche: "Yaw angle is, in fact, the "angle of attack";".
L'angolo di attacco non è sull'asse orizzontale?