The Night, Navigation, and Limited Visibility Manual is the text-book literary assistant to the SDI Night, Navigation, and Limited Visibility certification course. By signing up for this course, the perspective student will learn how to build upon their underwater navigation skills and integrate them with night diving adventures, with the challenge of diving in a limited visibility environment. This manual will give an in-depth understanding in a variety of topics, including underwater navigation gear, natural navigation, compass navigation, electronic navigation, night diving with limited visibility, and finally triangulation.