This book is NOT a full biography about Columbus. Rather, it is the insights of the author (Morison) as a sailor, who went with an expedition to recreate the voyages of Columbus. He tells the readers what Columbus got right or wrong, as a sailor, and how he was indeed the greatest sailor of his era. Sadly, Morison (incorrectly) linked Columbus with Indigenous genocide and modern-day revisionists gleefully repeat his statements, knowing that Morison contradictorily believed Columbus was a hero. I covered this subject in great depth in my book "Columbus Day vs Indigenous Peoples' Day" (chapter 26), if you are interested in learning more about it. In spite of it all, Morison's work is still one of the most important non-primary sources books on Columbus.