A system of navigation employing an emergency longitude slide ruler for stellar navigation is described. The emergency longitude slide ruler is equipped with several wheels having rulers with settings including of the longitude slide ruler of the present invention include year, date, hour, minutes, star angle measurement degree wheel, a longitude wheel, a circumpolar star field identifier wheel, star meridian transit angles wheel, and a time zone wheel. All wheels are of diminishing diameters and are laid on top of each other in descending circumference with minute gradations allowing each consecutive wheel to line up with its larger adjacent wheel according to proper settings to eventually indicate longitude. The system presents an efficient and expedient means by which an individual with very limited knowledge of navigation and celestial bodies can determine his or her location, including longitude.