"Afloat; or, Adventures on Watery Trails" is a nautical adventure novel written by Captain Alan Douglas. The novel follows the maritime adventures of its characters as they navigate through various challenges and experiences on the water.Unfortunately, there isn't a known author named Captain Alan Douglas who wrote a book titled "Afloat; or, Adventures on Watery Trails." It's possible that the title and author you provided are fictional or that the book was published under a different name or by an author with a different pseudonym.However, the theme of maritime adventures and nautical exploration has been a popular subject in literature for centuries. Many authors, including classics like Herman Melville ("Moby-Dick") and Robert Louis Stevenson ("Treasure Island"), have explored the adventures and perils of life at sea.