• About Navigation Charts
• Obtaining
Navigation Charts
About Navigation Charts Many charts of the Great Lakes are produced
and regularly updated by National Oceanic and Atmospheric Administration (NOAA).
Twenty-four charts are published for areas of Lake Michigan, for example, at
scales between 1:5,000 and 1:240,000. The entire lake is covered in a Mercator
projection at a scale of 1:500,000. (Great Lakes charts were produced by the Army
Corps of Engineers for many years, but this responsibility was transfered
to NOAA in the 1980's.) Obtaining Navigation
Charts NOAA also publishes
charts specifically designed for use by small craft, including motorized
pleasure boats and canoes. In Wisconsin, these charts cover Lake Winnebago and
the lower Fox River to its mouth on Green Bay, and are produced in a strip
chart format. Strip charts (in this case, bound in a book) are linear map
sections that cover a specific stretch of lake or river. Several NOAA
publications relate to nautical charts; they include tide tables, tidal current
and circulation charts, bathymetric maps, navigation data and regularly updated
notices for mariners. Navigation charts and small-craft charts are
available directly from NOAA. In addition, local dealers including sporting
goods shops and marinas often stock charts applicable to their region; in
Wisconsin, most of these are along the shores of the Great Lakes. For
additional information or to order maps, charts, or publications contact the NOAA.
Navigation aids for the Mississippi River are maintained by the Army
Corps of Engineers. Updated Upper Missippi River Navigational Charts
for 2002 are available for purchase as a 200-page book or as a free download
from the COE. Visit the Rock Island COE for individual chart downloads and
content revisions at www.mvr.usace.army.mil/NavCharts/UMRNavCharts.asp
Nautical charts are published at different scales depending on the intended
use. Harbor charts, published at scales of 1:50,000 and larger, are used
for navigation and anchorage in harbors and small waterways. Coast
charts are produced at scales from 1:50,000 to 1:150,000 for navigation in
nearshore coastal areas and large harbors. General charts are produced
at scales of 1:150,000 to 1:600,000, and are intended for offshore navigation,
but contain enough detail to allow the use of visual navigation aids or depth
soundings. Sailing Charts are produced at scales of 1:600,000 and
smaller, for offshore sailing between distant coastal ports and for approaching
the coast from the open water.
NOAA publishes several series of navigation and nautical maps
for coastal and offshore areas of the Great Lakes and oceans that border the
country. The maps are most commonly used for marine navigation. Navigation and
nautical charts contain a variety of information that pertains to lake and
ocean bottom topography, geodetic coordinates, hazards to navigation, open
water navigation, and approaches to harbors and ports.
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