This is definitely a text book. Written likely to be used in conjunction with a lecture of sorts, this book is excellent if you're teaching a course on the subject of post-medeival seafaring, however, it'd also be a good book is you're interested in the subject and don't mind fighting through a text book.
The book discusses the structural and functional evolution of watercraft after the medeival ages, the economic and political effects of naval construction and advancement, and discusses in detail a number of nautical archaeological excavations of important shipwrecks in the New World.