Left: “Knotted reflections of masts.” Right: “Broken reflection of sail. The mast, being taller, is reflected as a continuous winding line.”The book is called Light and Water: A Study of Reflexion and Colour in River, Lake, and Sea, by Sir Montagu Pollock. It gives a thorough analysis of reflections on smooth, rippled, and wavy water, with perspective diagrams and explanations. You can download it for free as a PDF at the Internet Archive.