Large Scale the fraction is larger (ie: 1/100,000); a closer view
Small Scale the fraction is smaller (ie: 1/500,000); shows more area
Chart Sources:
NOS Great Lakes and coastal waters of US
DMAHTC high seas and foreign water
CofE major inland rivers, canals, lakes


Gold land areas on NOS charts
White water
Blue shallow water areas
Green submerged water areas that uncover (tidal)
Magenta lighted buoys, red buoys, caution and danger symbols, compass roses
Black most symbols and printed information
Gray land areas on DMAHTC charts


Vertical objects dry at high water, not affected by movement of water
Leaning/Slanting features in water, underwater, or floating; not depth figures


Mean Lower Low Water average of all lowest water levels for 19 years---blue tint out to depth contour that is considered a danger contour for majority of marine traffic expected to use the chart
Mean High Water Line shoreline---datum used for vertical clearances of bridges
Low Water Line single row of dots, other contours represented by a series of dots or dots and dashes (see Chart No. 1)
Range Lines solid over navigated portion, dashed where it should not be followed


Sailing smallest scale, long stretches of coastline, open ocean between ports
General more limited area of coast, coastwise navigation, within sight of land
Coast Chart close-in coastwise navigation, entering and leaving harbors
Harbor largest scale, most detailed, navigation within harbors
Small-craft Chart compact, small-size, folded, public marine facilities available