Archive for the ‘Cartography’ Category

Celebrating Abe’s birthday! Lincoln’s slave density map is home again in President Lincoln Cottage   Leave a comment

The “slave density map,” created by the men of U.S. Coast Survey in 1861, is one of Coast Survey’s most treasured historical maps. Artist Francis Bicknell Carpenter included it in his painting, “First Reading of the Emancipation Proclamation of President Lincoln,” because Lincoln consulted it so often in devising his military strategy. According to Carpenter, President Lincoln used the map in his decisions to send his armies to free blacks in some of the highest density areas in order to destabilize Southern order.

Francis Bicknell Carpenter placed the "slave density map" in the lower right corner of his painting of the Emancipation Proclamation.

Francis Bicknell Carpenter placed the “slave density map” in the lower right corner of his painting of the Emancipation Proclamation.


President Lincoln’s Cottage, now maintained by the National Trust for Historic Preservation, is where President Lincoln developed the Emancipation Proclamation. So it was fitting that, on Lincoln’s birthday this year, NOAA’s Office of Coast Survey presented a copy of the map to Cottage officials, to assist with their vital educational programs.

In the very library where Lincoln may have studied the map, Coast Survey’s Dawn Forsythe (left) and NOAA’s Ben Sherman (right) presented the map to Erin Carlson Mast, the Cottage’s executive director, and Callie Hawkins, associate director for programs.

Dawn Forsythe (Coast Survey), Erin Carlson Mast and Callie Hawkins (Lincoln's Cottage), and Ben Sherman (NOAA) with the slave density map in the Lincoln Cottage library.

Dawn Forsythe (Coast Survey), Erin Carlson Mast and Callie Hawkins (Lincoln’s Cottage), and Ben Sherman (NOAA) with a copy of the slave density map in the Lincoln Cottage library.


The Cottage plans to use the map in their educational programs. To learn more about the map, see Mapping Slavery in the Nineteenth Century.

The men of Coast Survey created the map to help the public understand the secession crisis, by providing a visual link between secession and slavery.

The men of Coast Survey created the map to help the public understand the secession crisis, by providing a visual link between secession and slavery.

So you want to chart an artificial reef?   2 comments

There are literally millions of pieces of data on nautical charts. How do cartographers determine which data to put on the charts? Two Coast Survey cartographers, Paul Gionis and Lance Roddy, explained some of the processes, protocols, and NOAA charting requirements to participants at the Florida Artificial Reef Summit earlier this month. (See the archived video of their presentation, starting at 55:40.) Among their many duties, these cartographers are responsible for vetting artificial reef public notices and permits from the U.S. Army Corps of Engineers, and for acquiring source data from the state and county reef coordinators.

By explaining the nautical chart aspects of planning, creating, and maintaining fish havens, they hoped to smooth out the permitting and charting phases.

(By the way, in case you’re wondering what we mean by “fish haven,” Coast Survey’s Nautical Chart Manual defines them as “artificial shelters constructed of rocks, rubble, boxcars, boats, concrete, special designed precast structures to enhance fish habitats, remnants of oil well structures, etc., that are placed on the sea floor to attract fish. Fish havens are often located near fishing ports or major coastal inlets and are usually considered hazards to shipping. Constructed of rigid material and projecting above the bottom, they can impede surface navigation and therefore represent an important feature for charting.”)

Permits issued by the Army Corps of Engineers are the sole source for classifying obstructions as artificial reefs and fish havens for charting purposes. Specific essential information needs to be provided for charting the areas.

  • Cartographers need accurate geographic coordinates and dimensions, and the “authorized minimum clearance” (safe vessel clearance) for each distinct reef boundary.
  • Importantly, the designated area cannot conflict with charted features. For instance, we cannot designate artificial reefs or fish havens in safety fairways, restricted areas, anchorages, or entrance channels. It almost goes without saying that we also don’t want to place reefs in missile test areas, or areas with pipelines, cables, or unexploded ordnance.
  • The cartographers must receive notice of deployment (telling us that construction has begun).

A good example of how Coast Survey works on charting artificial reefs is the initial reef proposal for Port Everglades chart 11466. The initial proposal designated a minimum clearance of 7 feet – which would prevent a mariner from transiting the area even though the water is very deep. The proposed reef area also conflicted with two established anchorages for commercial ships waiting to enter the port.

Initial reef proposal

Initial reef proposal


After working with the Corps of Engineers and project planners, Coast Survey was able to split the area and chart three separate bands with progressively deeper minimum depths, from seven feet to 60 feet of clearance. They also avoided overlap with the charted anchorages. The solution prevented navigation conflicts and protected the artificial reef.

Charted fish havens were banded progressive depths, excluding anchorages

Charted fish havens were banded by progressive depths, and excluded anchorages.

The cartographers appreciated the chance to talk directly to Florida’s artificial reef community. “Events like these provide an expansive avenue to articulate Coast Survey requirements for promoting safe and efficient navigation,” Gionis points out.

Coast Survey’s navigation manager for Florida, Mike Henderson, is our charting representative on the ground in that state, and is available to work on future projects as well as answer charting inquiries in general.

Coast Survey improves access to data on thousands of wrecks and obstructions   6 comments

Knowing the locations of shipwrecks and other obstructions has always been important for safe navigation ‒ but mariners are not the only people who want to know about wrecks. They are also important for marine archeology, recreational diving, salvage operations, and fishing, among other interests. Now, Coast Survey has improved our Wrecks and Obstructions Database, giving everyone easy access to new records to explore.

Web-based map of wrecks

Coast Survey’s wrecks and obstructions database provides info on thousands of wrecks.

Historically, Coast Survey has maintained two separate sources of information on wrecks. We recently combined the sources, bringing together information on nearly 20,000 wrecks and obstructions.


Coast Survey established the Automated Wreck and Obstruction Information System (AWOIS) database in 1981 to help estimate the level of effort required to investigate items during a planned hydrographic survey, but maritime users were also interested in AWOIS’ historical records. However, because the emphasis is on features that are most likely to pose a hazard to navigation, AWOIS has always had limitations. Most notably, AWOIS is not a comprehensive record and does not completely address every known or reported wreck. Additionally, for a number of reasons, AWOIS positions do not always agree with a charted position for a similar feature.


Coast Survey compiles NOAA’s electronic navigational charts (NOAA ENC®) from sources on features that are navigationally significant. As the official chart data used in electronic chart and display information systems (ECDIS), ENCs are the authoritative source of information about known or reported wrecks and are much more comprehensive than AWOIS. However, the features in an ENC typically lack the historic information and context provided by AWOIS.


Correcting for some overlap between the two source databases, Coast Survey’s new wrecks and obstructions database now contains information on about 13,000 wreck features and 6,000 obstructions. Wreck features from each original database are stored in separate layers but can be displayed together. Users may also choose a background map from several options.

The new database also offers users additional data formats from which to choose. Historically, shipwreck data in AWOIS was available in Adobe PDF and as Microsoft Access Database (MDB) format. More recently, KML/KMZ files replaced PDF and MDB formats, making it easier for public users to view AWOIS data, by using freely available software such as Google Maps or Google Earth. Now, in addition to KML/KMZ and Microsoft Excel formats for general users, Coast Survey provides the data in ArcGIS REST services and OGC WMS services, for use in GIS software programs or web-based map mashup sites.

Coast Survey unveils NOAA ENC Online enhancements   1 comment

In November 2013, we introduced NOAA ENC Online – a continuous viewer for our electronic navigational charts. You can click on the web map and zoom to selected features or locations, to see the information contained in over a thousand electronic charts of NOAA-charted waters. Each zoom moves you through an ENC depiction that takes into account the ENC scale and other attributes that are encoded in the ENC, allowing features to become visible or invisible as you seamlessly zoom in and out of the data.

NOAA ENC Online is based on Esri’s Maritime Chart Server.

Now this latest release of NOAA ENC Online lets you:

  • Set a shallow and deep depth contour, which changes the shading to those parameters
  • Set a safety contour (In electronic charting systems, the safety contour is set based on the ship’s draft changes the depiction of rocks, wrecks and obstructions to isolated dangers depending on if the water is “safe” or “unsafe” for vessel navigation.)

ENConline Safety contour

  • Change between S-52 simplified and S-52 traditional symbols


  • Change the background colors of the display based on the S-52 color palette for different light conditions on the bridge of a ship

ENConline color palette

  • Turn off certain features based on different categories such as buoys and traffic routes

ENConline layers switching on and off

NOAA ENC Online is not certified for navigation. It does NOT fulfill chart carriage requirements for regulated commercial vessels under Titles 33 and 46 of the Code of Federal Regulations.

Geographic names disappear from charts, but not from history — #Data4Coasts   Leave a comment

by Meredith Westington, Coast Survey geographer

Good, informed decisions are often based on analyses of historic and present conditions. Researchers, decision-makers, and amateur history buffs find detailed documentation of past conditions in the thousands of Coast Survey charts, dating back to the mid-1800s, in our Historical Map and Chart Collection.

Just like present day nautical charts, historic charts contain a wealth of information about geographic features — including their names, shape, and condition. Geographic names are important locational references for today’s emergency responders, but current and historic names also convey important aspects of local people and culture, which may persist through time.

As Coast Survey’s nautical cartographers routinely apply new topographic and hydrographic data to improve decisions at-sea, a question arises about names when a geographic feature, such as an island, bay, or bayou, has changed: does the associated place name disappear when the geographic feature is no longer there, or does the local population still use the historic name to convey a shared sense of place?

Coast Survey cartographers raised this exact question after applying new shoreline information to charts covering Louisiana. When cartographers applied new shoreline data to charts 11358 and 11364 in 2011, they found that named features were no longer there (see the images below for a comparison of today’s landforms vs. the historic landforms in 1965). In early 2013, another new shoreline survey similarly affected fourteen geographic names on chart 11361. They removed these “dangling names” to reduce chart clutter, but are there new names for the areas where the features used to be?

chart comparisons

On the left is the area south of Buras, Louisiana, on Mississippi River chart 11364, 2012 edition. On the right is the same area shown on Mississippi River chart 1271, 1965 edition.

Losing places (and their names) may mean losing important locational references. Some of these places have appeared on NOAA’s nautical charts of Louisiana since the late 1800s, so their removal raises concerns about a loss of cultural identity on the landscape. For example, Cyprien Bay was named for longtime resident Cyprien Buras. The names live on, of course, on the historic maps and charts in Coast Survey’s Historical Map and Chart Collection. Importantly, they are also retained in the lesser-known U.S. Board on Geographic Names’ federal repository of place names, the Geographic Names Information System. The system’s current and historical records make a great starting point for finding names that you can use to locate relevant historical nautical charts in the Historical Map and Chart Collection. The collection has an easy-to-use geographic place name search function. Just type in a name, and start to explore our nation’s geographic changes…

Search over 35,000 historical maps and charts.

Search over 35,000 historical maps and charts, just using a geographical name.

Great Lakes mariners get new NOAA nautical chart for St. Mary’s River   1 comment

Vessel operators transiting St. Mary’s River, between Lake Superior and the lower Great Lakes, have a new nautical chart to help lessen the dangers inherent in this narrow and complicated waterway. The first edition of Chart 14887 (St. Marys River – Vicinity of Neebish Island) is available this week as a paper print-on-demand chart, PDF, and raster navigational chart. The electronic navigational chart will be available by March, in time for the beginning of the shipping season. (UPDATE, 2/12/14: NOAA ENC US5MI50 is now available.)

Coast Survey has built the chart from original sources, providing the highest standard of accuracy for hydrographical and topographical features and aids to navigation. The chart provides large-scale (1:15,000) coverage of the up bound and down bound channels of the St. Mary’s River – one of the busiest waterways in the nation. Over 4,100 transits of commercial and government vessels move about 75 million tons of cargo through the 300-day shipping season.

Corrected shoreline, chart 14883

The red lines show the shoreline as depicted before the updates. NOAA cartographers are applying the corrected shoreline and feature positions to the new chart and new editions of current charts in the Great Lakes.

Chart 14887 uses updated shoreline data, collected with NOAA’s high tech remote sensing planes. (See National Geodetic Survey’s shoreline data viewer.) At the 1:15,000 scale, the positions of many of the features were corrected an average of ten meters from positions in prior charts, a vital correction for precision navigation by vessels that can exceed a thousand feet long.

Coast Survey also plans to issue new editions of the current four largest scale charts of the St. Mary’s River in late January. Charts 14882, 14883, 14884 and 14962 will have all new shoreline, updating the locations of features and aids to navigation. These updates for the St. Mary’s River follow 21 new editions for Great Lakes charts from Buffalo to Thunder Bay Island, around the Lower Peninsula to Milwaukee Harbor and Ludington. More updates are slated for 2014 and 2015.

Chart 14887 was compiled by Nathan Burns and reviewed by Laurie Bennett, under the direction of Marine Chart Division branch chief Andy Kampia.

Iron ore shipment on Lake Superior

Updates to NOAA’s Great Lakes nautical charts will benefit ships like this one, carrying iron ore on Lake Superior. Photo courtesy of Carolyn St. Cyr.

Happy holidays to chartmakers in the U.S. and around the world   2 comments

Holiday card 2013


Get every new post delivered to your Inbox.

Join 10,566 other followers