The US Power Squadron back in the pre-GPS 1980s used &#x27;The American Practical Navigator-An Epitome of Navigation (1966)&#x27; as their primary reference book. My grandfather ran one of the courses. Amazon(US) has a reprint of the 2002 version:<p><a href="http:&#x2F;&#x2F;www.amazon.com&#x2F;The-American-Practical-Navigator-Bowditch&#x2F;dp&#x2F;0939837544" rel="nofollow">http:&#x2F;&#x2F;www.amazon.com&#x2F;The-American-Practical-Navigator-Bowdi...</a><p>But you can study it online gratis at:<p><a href="https:&#x2F;&#x2F;en.wikisource.org&#x2F;wiki&#x2F;The_American_Practical_Navigator" rel="nofollow">https:&#x2F;&#x2F;en.wikisource.org&#x2F;wiki&#x2F;The_American_Practical_Naviga...</a>