How does Patrick O'Brian use imagery in The Mauritius Command?

Imagery:

The topsails flashed out, the frigate's head swung to the north-east and steadied: she heeled, steeper and steeper as the courses, topgallants and staysails were sheeted home in smooth succession and the way came on her, the water slipping fast and faster still along her side. She shaved the cruel reef off Saint-Denis, altered course two points to eastward, and setting a flying-jib she stretched for the Ile de la Passe, making her ten knots watch after watch, her wake a straight green line of phosphorescence in the dark."

Jack glanced around, and there in fact was a most strikingly handsome woman, young, spry, a lady very much alive, wearing a green riding-habit; she was aware of being looked at, and she moved with even more grace than nature had provided.