Latitude, longitude, and geographic coordinates

Bowditch Ch. 1 §101

Bowditch Ch. 1 §101 — Introduction to Marine Navigation Marine navigation is the art and science of determining a vessel's position and conducting it safely from one point to another. Its four primary methods are dead reckoning, piloting, celestial, and electronic — modern voyages combine all four with electronic navigation as the principal real-time reference and the others as cross-checks.

Bowditch Ch. 15 §1501

Bowditch Ch. 15 §1501 — Navigational Astronomy Celestial navigation determines position from observations of celestial bodies. Although no longer the primary navigation method, it remains the back-up of last resort if all electronic systems fail.

Bowditch Ch. 4 §402

Bowditch Ch. 4 §402 — Nautical Charts The Mercator projection presents lines of latitude and longitude as straight lines crossing at right angles, with rhumb lines (constant bearings) appearing as straight lines. Distances must be measured at the latitude of the line, since meridian length varies with latitude.

Bowditch Ch. 7 §701

Bowditch Ch. 7 §701 — Bearings and Lines of Position A line of position (LOP) is a line along which the vessel is known to lie at a given moment based on a single observation. A fix is the intersection of two or more LOPs taken simultaneously.

33 CFR §100.01

§ 100.01 § 100.01 Purpose and intent. (a) The purpose of the regulations in this part is to provide effective control over regattas and marine parades conducted on the navigable waters of the United States so as to insure safety of life in the regatta or marine parade area. (b) Geographic coordinates expressed in terms of latitude or longitude, or both, are not intended for plotting on maps or charts whose referenced horizontal datum is the North American Datum of 1983 (NAD 83), unless such geographic coordinates are expressly labeled NAD 83. Geographic coordinates without the NAD 83 reference may be plotted on maps or charts referenced to NAD 83 only after application of the appropriate corrections that are published on the particular map or chart being used. [CGFR 63-22, 28 FR 5155, M…

33 CFR §151.06

§ 151.06 § 151.06 Special areas. (a) For the purposes of this part, the navigational descriptions of the special areas are as follows: (1) The Mediterranean Sea area means the Mediterranean Sea proper including the gulfs and seas therein, with the boundary between the Mediterranean and the Black Sea constituted by the 41° N parallel and bounded to the west by the Straits of Gibraltar at the meridian of 5°36′ W. (2) The Baltic Sea means the Baltic Sea proper with the Gulf of Bothnia, the Gulf of Finland, and the entrance to the Baltic Sea bounded by the parallel of the Skaw in the Skagerrak at 57°44.8′ N. (3) The Black Sea area means the Black Sea proper with the boundary between the Mediterranean Sea and the Black Sea constituted by the parallel 41° N. (4) The Red Sea area means the R…