The latest edition of the Bowditch. This version is Volume 1 only.I am honored to welcome you to the 2017 edition of Publication No. 9, The American Practical Navigator, or as most mariners refer to it, "Bowditch." As a young Surface Warfare Officer serving in my first ship, I quickly learned Bowditch should be my first resource for all things related to navigation, oceanography and meteorology. I never imagined that 25 years later, I would be privileged to lead the team entrusted with updating this incredible document.One can hardly imagine the time, effort, and pressure involved in undertaking such a task--this is Bowditch, after all. None of us alone can equal the talent, experience and skill of Nathaniel Bowditch, as expressed in his first edition of 1802. As a result, this edition is the outcome of countless hours of hard work by many dedicated, passionate, and skilled colleagues from a variety of disciplines. And it was this team of scientific and operational navigation experts, led by Dr. Jerry Clifford, which has created this contempo­rary edition that stands ready to address the challenges faced by today's navigators and mariners. Please take the time to read the long list of contributors to this edition, I know you will be impressed by the depth and quality of our team.Since the last edition, there have been huge advance­ments in positioning methodologies and navigation systems. In some cases, what was old is new again, so we focused considerable effort into improving the celestial navigation and piloting chapters. Hand-plotting latent fixes on paper charts has been overtaken by Electronic Chart Display and Information Systems that continuously tell you where you are, provide warnings when standing into danger, and display radar and Automatic Identification System information to heighten situational awareness. Older graphics have been replaced by newer, higher resolution images to better illustrate the purpose of the text. And, we have tried to make this document more accessible by creating it in an electronic format which allows easier updating and online publication.I do understand the desire for a hard copy Bowditch, but publishing costs have served to actually decrease our ability to include all of the information we wanted to make available to the mariner (this electronic version has 2 full volumes!). Needless to say, we are justifiably proud of this 2017 edition and equally honored to continue such a note­worthy legacy of th