Marine Nautical Charts

the principal type of marine map; it is used for navigation and to ensure safety while navigating.

Marine nautical charts are usually drawn in the conformal normal cylindrical Mercator projection, which makes it possible to lay out the ship’s constant compass course (rhumb line) as a straight line. The basic elements of marine nautical charts are shown by conventional signs and include the shoreline with an indication of the nature of the shores, the relief of the sea bottom, navigational dangers (cliffs, reefs, sunken ships, underwater obstacles), aids to navigation (light beacons, illuminated signs, radio beacons, buoys, markers), channels, mooring places, various test grounds and regions in the water, characteristics of the ground of the bottom, navigational orientation points, specific hydrological data, rivers, land relief, the road network, and population centers.

Each marine nautical chart has a number and a name. Depending on the purpose and scale, various types are distinguished—plans, special charts, and route and general charts.

Plans (scales of 1:500–1:25,000) are used for bringing ships into ports, harbors, and roadsteads and when moving ships and anchoring them. Special charts (scales of 1:25,000–1:75,000) are designed to assist navigation in the immediate vicinity of shores and through skerries and when passing through narrow sections and canals. Route charts (scales of 1:100,000–1:500,000) are primarily used when sailing along coasts at a considerable distance from them. General charts (scales of 1:750,000–1:5 million) are intended for general study of the navigational and hydrographic conditions of the sailing region, laying out the ship’s path ahead of time, and navigating on the open sea or ocean.