We both started a 13-week course on Sailing and Seamanship. This was three hours per week in an academic setting, which covered 14 chapters of information. It culminated with a written and graded final examination. It was a humbling and enjoyable experience for both of us. If you understand why an airplane flies this is much the same.
Air passing over the sail or over the wing creates a low- pressure area on the reverse side.
This happens because of the curvature of the sail or curve of the airfoil. The low-pressure area actually pulls you along in a boat or lifts you if you re flying. In a boat, the keel keeps you from slipping sideways too much and yields a resultant force forward which moves the boat. Understanding this makes trimming the sails and basic maneuvering more easily understood. Another topic which proved very useful was Marlinspike Seamanship.