Navigating waters before GPS: Why some mariners still refer to Loran-C

by Nick Perugini

One of the most popular recurring questions received by NOAA’s Office of Coast Survey involves customers – typically fishermen – wanting to obtain a chart with a Loran-C navigation grid on it. Here are a few inquiries from NOAA’s Nautical Inquiry & Comment System:

  • Hello, I was wondering if it is still possible to purchase or locate older editions of Lake Huron charts (14862-3-4) with the LORAN-C overlay. Many older wrecks and reported snags are still in Loran and have not been converted to GPS. Artificial algorithms are difficult to use when plotting grids. Any help you can give me is much appreciated.
  • Is it possible to access Loran-C charts of New England from prior to 2009 when NOAA stopped published with the LORAN-C lines? THANKS!
  • I was wondering if there was a way for me to buy a chart that has LORAN lines and notes on it? I understand that all of the new charts no longer have this information on them. I am most interested in Chart 11520, Cape Hatteras to Charleston. I didn’t know if there might be an archived form of this chart that shows the LORAN features. Any help in finding a chart like this would be greatly appreciated.

A quick history lesson on Loran-C: Loran (Long range navigation) was a hyperbolic radio navigation system developed in World War II. Loran grid lines (actually hyperbolas) first appeared on nautical charts during the 1950’s. The intersection of these electronic lines of position generated from shore transmitters provided mariners with accurate positions, within hundreds of feet, as their vessels operated nearshore as well as many hundreds of miles offshore. In the 1970’s, the U.S. Coast Guard (USCG) upgraded Loran-A to Loran-C, a system that was even more accurate and much easier to use.

However, positioning technology marches on. With the dawning of a high accuracy Global Positioning System (GPS) in the early 1990s, Loran-C slowly became antiquated and finally the USCG took Loran-C transmitting stations offline in 2010. With no Loran-C signal, Coast Survey followed suit and began to eliminate Loran-C lattices from nautical charts. Most charting customers welcomed the removal of the busy lattices from the chart as it made the chart more readable.

The entrance to the Chesapeake Bay, Chart 12221, with a Loran-C grid on the 2009 edition (left) and without Loran-C (right).
The entrance to the Chesapeake Bay, Chart 12221, with a Loran-C grid on the 2009 edition (left) and without Loran-C (right).

So why do some people still want nautical charts with a Loran-C lattice? Prior to GPS, many fishermen and commercial diving operations did not use a true latitude and longitude (Lat/Lon) geographic coordinate system to position their offshore features. They identified their favorite fishing or diving locations by Loran-C time delay coordinates. When Loran-C lattices were removed from NOAA charts, many fishermen were left with Loran-C coordinates that had no corresponding Lat/Lon. Therefore, they did not have a way of plotting their Loran-C coordinates on current charts.

The Office of Coast Survey Historical Map & Chart Collection provides one way to address the problem. Users can find editions of their charts published prior to 2010 that would likely contain a Loran-C lattice. While historical charts should not be used for navigation today since they have not been updated, they can be used to convert Loran-C coordinates to Lat/Lon (GPS coordinates). Customers can download charts as high-resolution images, transfer the files to a flash drive, and take it to a local printer who can print the charts in a large format. Alternatively, some electronic chart systems allow you to display Loran-C lattices over current up-to-date charts, or to import a chart image, define its Lat/Lon origin, and utilize it with chart plotter software.

So is Loran gone forever? Not quite. In fact, Loran is making a comeback as Enhanced Loran, i.e. “eLoran.” With increased awareness of the vulnerabilities of satellite positioning systems, there is a growing consensus in the national security community that an independent back-up positioning system is required. The USCG and other organizations within the Department of Homeland Security are conducting tests on eLoran. Like the original Loran-C, the new system would have shore-based transmitters that generate hyperbolic grids. Unlike the old system, eLoran would be much more accurate with differential corrections built into the signal transmissions. When and if eLoran comes to fruition, you will not see Loran grid lines returning to NOAA charts since receivers will likely be working in a Lat/Lon coordinate system.

NOAA releases documentary on women’s service in the NOAA Corps

As Women’s History Month draws to a close, NOAA announces the release of Women of the NOAA Corps: Reflections from Sea and Sky, a documentary that highlights the important role women play in the NOAA Commissioned Officer Corps.

Women of the NOAA Corps is a 31-minute historical documentary on the lives and stories of ten women in the NOAA Corps service: how they came to the NOAA Corps, their motivations and challenges, and views on their service.

The documentary serves to elevate public understanding and appreciation of the NOAA Corps, particularly women’s service in the Corps, and to inspire the next generation of women in scientific service. The NOAA Corps is one of seven federal uniformed services of the United States, and NOAA Corps officers serve on the sea, on land, and in the air to support NOAA’s environmental science and stewardship mission.

The project was funded through the 2016 NOAA Preserve America Initiative Internal Funding Program.

Rear Adm. Harley Nygren (NOAA ret.) and Cmdr. Pam Chelgren-Koterba (NOAA ret.). Nygren was the first director of the NOAA Corps and penned entry for women to serve. Chelgren was the first woman to join the NOAA Corps in 1972, under Nygren’s leadership.
Rear Adm. Harley Nygren (NOAA ret.) and Cmdr. Pam Chelgren-Koterba (NOAA ret.). Nygren was the first director of the NOAA Corps and penned entry for women to serve. Chelgren was the first woman to join the NOAA Corps in 1972, under Nygren’s leadership.
The production team interviewed two film subjects on location at the Aviation Operation Center in Tampa, Florida. (Left to right) Bob Schwartz (NOAA Office of Communications), Crescent Moegling (Co-Producer; NOAA Office of Coast Survey), Lt. j.g. Shanae Coker (NOAA Corps), Timi Vann (Producer; National Weather Service), and Cmdr. Cathy Martin (NOAA Corps). The team also included Lt. Cmdr. Fionna Matheson as a technical advisor and worked under the leadership endorsement of Rear Adm. Anita Lopez (NOAA ret.).
The production team interviewed two film subjects on location at the Aviation Operation Center in Tampa, Florida. (Left to right) Bob Schwartz (NOAA Office of Communications), Crescent Moegling (Co-Producer; NOAA Office of Coast Survey), Lt. j.g. Shanae Coker (NOAA Corps), Timi Vann (Producer; National Weather Service), and Cmdr. Cathy Martin (NOAA Corps). The team also included Lt. Cmdr. Fionna Matheson as a technical adviser and worked under the leadership endorsement of Rear Adm. Anita Lopez (NOAA ret.).

Coast Survey in World War 1: “an instant and eager response to the country’s call for help”

On April 6, 1917, the United States declared war on Germany, in the World War that began three years earlier, when Archduke Franz Ferdinand was assassinated. By 1918, over 30 percent of Coast and Geodetic Survey personnel were on active duty with the Army and Navy. With 272 members of the C&GS in active military service, and 5 survey vessels transferred into naval service, the Survey curtailed much of their regularly scheduled hydrographic work. Instead, personnel directed most of their energies to the assistance of the military branches, with the remaining hydrographic parties conducting special confidential surveys for the Navy Department.

Military map 1918
In one example of support for the military, the U.S. Coast and Geodetic Survey prepared this military map in 1918 for the U.S. Signal Corps.

 

The C&GS 1918 annual report briefly mentioned some of the hydrographic projects:

“Special hydrographic examinations were made by means of the wire drag at points designated by the Navy Department. Among such were the wire-drag surveys in Long Island Sound and in York River (Chesapeake Bay). Quite an extensive wire-drag examination was made of the waters in the vicinity of Eastport, Me. Initial surveys included such work as the location of points for naval fire-control experiments, the reestablishment of the speed-trial course at Lewes, Del., for torpedo-boat destroyers, the location of the Port Jefferson trial course in Long Island Sound, and the Block Island (Rhode Island) trial course.”

Wire drag 1917
This C&GS launch is involved in the wire drag survey off Block Island, 1917

 

Additional war projects included:

  • Survey of Hampton Roads naval base, for extensive improvements
  • Surveys around the coal piers at Newport News and in the Newport News dredged channel in Hampton Roads, to meet the needs of the Navy Department
  • Surveys of the approaches to Portsmouth Harbor NH, approaches to Narrangansett Bay, Long Island Sound, Florida reefs, Cape Cod Canal, and Plymouth Harbor, to “meet the needs of the Navy Department”
  • Layout of a one-mile trial course at Alexandria VA, for naval vessels

Additionally, the Navy asked for a survey of the Virgin Islands. In addition to the general survey for the Navy, local naval officials requested a number of small surveys. According to the Coast and Geodetic Survey Annual Report, 1918:

“One topographic party was started on the sheet embracing the town and harbor on April 22. The other party was started on the western sheet May 1. Both continued with only short interruptions for signal building and triangulation the balance of the fiscal year.

“Extreme care was taken to obtain accuracy on the sheet covering the town. An elaborate. control was furnished. The contours were determined with more than ordinary precision, due to the fact that the local government is contemplating installing a water system in the vicinity, and the Coast Survey chart would be studied for a waterworks site.

“At the request of the Navy Department particular stress was given the locating of old ruins, stone walls, boundary monuments, etc. All of this topography was done on a 1:10,000 scale. Twenty-foot contours were determined.

“At the request of the local authorities a special topographic survey was made of a piece of alien property which it was contemplated to seize for military purposes. This survey consisted in locating the shore line, docks, houses, and contours.”

(See chart 905, Virgin Islands, Virgin Gorda to St Thomas and St Croix, 1921, and chart 906, Virgin Passage and Vieques Sound, 1922)

As happened during the Civil War, Coast and Geodetic Survey ramped up their chart production for the war effort – as well as for the United States Shipping Board, formed in 1917 to promote the development of an American merchant marine, and to address shipping problems during time of war.

Map and chart production in 1919 was 136 percent greater than for the year 1915.

In the annual report of 1919, Capt. E. Lester Jones, Coast and Geodetic Survey director from 1915 to 1929, paid tribute to the service of all C&GS personnel through the war:

“This service has 103 years of active history which show that it has never failed in loyalty, no matter what the call. Its members have always given the benefit of their trained thought and well-informed judgment whenever and wherever they were needed and however they could best be used.

“In the great conflict just ended these traditions have been upheld.

“Admiration is due the spirit that has animated each and every member of the United States Coast and Geodetic Survey. To a man there was an instant and eager response to the country’s call for help. At all times, a service which is laboring for the safety of mankind, it stood ready to undertake new work. The kind of work needed was varied-all could not go into battle. The men in the field would have been useless without the executive work behind them at home, and all honor is due them, who, showing a steady, uncompromising moral courage, unmoved by clamor and undisturbed by outer excitement, have kept steadily at their posts, carrying on most successfully the important and necessary work here.

“Those who were sent to the field were simply performing their duty in another way, and established an enviable and remarkable record, showing again their unusual adaptability and training.

“The Bureau was about equally represented in both Army and Navy and performed signal valuable service in each.”

ADDITIONAL READING:

“The 200th Anniversary of the Survey of the Coast,” Prologue Magazine, by John Cloud; National Archives, Spring 2007, Vol. 39, No. 1

 

It wasn’t just Jefferson. Congress initiated Coast Survey legislation, approved #OTD 210 years ago

On this date in 1807, President Thomas Jefferson approved an act to provide for surveying the coasts of the United States. NOAA has long honored Jefferson — but what of the legislators who saw the need, wrote the bill, and sent it to the president?

On December 15, 1806, Samuel W. Dana (CT) introduced a resolution instructing the House of Representatives’ Committee of Commerce and Manufactures to “inquire into the expediency of making provision for a survey of the coasts of the United States, designating the several islands, with the shoals and roads, or places of anchorage, within twenty leagues of any part of the shores of the United States.” Dana was joined in debate by Jacob Crowninshield (MA-2), the chair of the Committee of Commerce and Manufactures.

Samuel Dana (left) represented Connecticut in Congress from 1797 to 1821. Jacob Crowninshield, of the famed American maritime family, chaired the House Committee on Commerce and Manufactures in the 9th Congress.
Samuel Dana (left) represented Connecticut in Congress from 1797 to 1821. Jacob Crowninshield, of the famed American maritime family, chaired the House Committee on Commerce and Manufactures in the 9th Congress.

 

The contemporary report of the House debate gives us some understanding of the act’s provisions. (From the History of Congress, H. of R., pages 151 and 152)

Mr. Dana, of Connecticut. – In 1802, an act was passed, authorizing a survey of Long Island Sound. In pursuance of that act, the Secretary of the Treasury caused a survey to be taken by two men, who appear to have been, what the act intended, intelligent and proper persons. And there has since been published a chart of the Sound, handsomely executed, on a large scale, which must, I presume, be regarded as convenient and valuable by those concerned in that branch of navigation.

At the last session of Congress, an act was passed for another survey. It made provision for surveying the coast of North Carolina between Cape Hatteras and Cape Fear, with the shoals lying off or between those capes. I understand that measures have been taken for executing this act, but that the vessel employed in the service, and all the papers respecting the survey which had been made, had been lost near Ocracoke Inlet, in one of the desolating storms experienced on the coast in the course of the present year.

The surveys, which have thus been authorized, were perhaps of the most urgent necessity; but other surveys of the coast are desirable. What has already been done may be regarded as introductory to a general survey of the coasts of the United States under authority of the Government. With a correct chart of every part of the coast, our seamen would no longer be under the necessity of relying on the imperfect or erroneous accounts given of our coast by foreign navigators. I hope the lives of our seamen, the interest of our merchants, and the benefits to the revenue, will be regarded as affording ample compensation for making a complete survey of the coasts of the United States, at the public expense.

The information which may be obtained will also be useful in designating portions of territorial sea to be regarded as the maritime precincts of the United States, within which, of course, the navigation ought to be free from the belligerent searches and seizures.

It is proposed to extend the survey to the distance of twenty leagues from the shore. This distance is mentioned with a view to the second article of the treaty with Great Britain in 1783, which describes our boundaries as “comprehending all islands within twenty leagues of any part of the shores of the United States.”

The resolution, which I propose for the consideration of the House, is expressed in these words:

Resolved, That the Committee of Commerce and Manufactures be instructed to inquire into the expediency of making provision for a survey of the coasts of the United States, designating the several islands, with the shoals and roads or places of anchorage within twenty leagues of any part of the shores of the United States.

[end Dana]

Mr. Crowninshield, of Massachusetts, was very glad to see the resolution offered, but he should like it better if it were more extensive. He believed there were many shoals on the coast lying at more than twenty leagues distance from the shore. Among others, St. George’s Bank was at more than this distance. He wished that the resolution might be varied so as to comprehend all the shoals on the coast, from St. Croix to the southern extreme of Louisiana.

Mr. C. had always thought it important that an accurate survey should be made of our coast. Holland’s chart, though the best, is very inaccurate.

Mr. Dana accorded with the chairman of the Committee of Commerce and Manufactures (Mr. Crowninshield) in respect to the utility of an accurate survey of the shoal which he had mentioned, but was against altering the resolution so as to include any islands at a greater distance than twenty leagues from the shore. The treaty of 1773 (sic) authorizes us to consider islands within that distance as appertaining to the territory of the United States. There is, therefore, peculiar propriety in extending the proposed survey to the distance of twenty leagues along the whole of our coast. If any shoals at a greater distance from shore are to be surveyed, special provision for this purpose may be made in the details of a bill which the committee may report. It would be more convenient to specify the details in a bill than in a general resolution for inquiry.

Mr. Crowninshield then moved to strike out twenty and insert fifty in the resolution. He was confident that there were shoals lying more than twenty leagues distant from the shore, and he thought it important to have them surveyed. It might be that there are no islands beyond that distance. He was not certain in regard to them, but he was sure that there were extensive shoals.

Mr. Dana suggested that the gentleman (Mr. Crowninshield) might designate, by way of amendment, particular shoals which he wished to be surveyed.

Mr. Cook, of Massachusetts, doubted whether all of St. George’s Bank was within even fifty leagues of the shore. If it were in order, he would move to strike out twenty and insert seventy.

A division of the question on striking out twenty and inserting fifty was called for.

Mr. Crowninshield at length withdrew his motion, and it was agreed that the resolution should lie on the table.

Dana’s resolution was referred to Crowninshield’s committee the next day and, on January 6, 1807, the committee introduced H.R. 21, authorizing and requesting President Jefferson to “cause a survey to be taken of the coasts of the United States.” After some amendments, the House passed the bill on January 20, and sent it to the Senate. The Senate also had some amendments, which the House concurred with. Both Congressional chambers approved the final bill on February 9, and the bill was “laid before the President of the United States.”

Public Acts of Congress, Annals of Congress, 9th Congress, 2nd Session, pages 1254 and 1255

An Act to provide for surveying the coasts of the United States

Be it enacted &c., That the President of the United States shall be, and he is hereby, authorized and requested to cause a survey to be taken of the coasts of the Untied States, in which shall be designated the islands and shoals, with the roads or places of anchorage, within twenty leagues of any part of the shores of the United States; and also the respective courses and distances between the principal capes, or head lands, together with such other matters as he may deem proper for completing an accurate chart of every part of the coasts within the extent aforesaid.

Sec. 2. And be it further enacted, That it shall be lawful for the President of the United States to cause such examinations and observations to be made, with respect to St. George’s bank, and any other bank or shoal and the sounding and currents beyond the distance aforesaid to the Gulf Stream, as in his opinion may be especially subservient to the commercial interests of the United States.

Sec. 3. And be it further enacted, That the President of the United States shall be, and he is hereby authorized and requested, for any of the purposes aforesaid, to cause proper and intelligent persons to be employed, and also such of the public vessels in actual service, as he may judge expedient, and to give such instructions for regulating their conduct as to him may appear proper, according to the tenor of this act.

Sec. 4. And be it further enacted, That for carrying this act into effect there shall be, and hereby is appropriated, a sum not exceeding fifty thousand dollars, to be paid out of any money in the Treasury, not otherwise appropriated.

Approved, February 10, 1807

signatures-1807

 

What does a zip file have to do with historic slave ship AMISTAD?

History is never completely written. There are always new discoveries, new understanding.

NOAA historian John Cloud recently sent Coast Survey an intriguing report:

Yesterday I was looking for some historic Chesapeake Bay T sheets [topography drafts]…  Anyway, down in the bottom of a folder, there was a zipped file, dated 2009, never unzipped. I thought: well, since I have noticed this now, why don’t I unzip it? It turned out to be two overly rescaled jpgs, but using my Keith Bridge tricks [a technique developed by a former Coast Survey historical chart expert] I found the two full-scale originals. It was one chart, with a small part cut off to make two separate files: the original 1838 hydrography for New Haven Harbour!

This is the basis for the 1838 engraved chart for Congress, the second published Coast Survey chart. (The first was based on Lt. Gedney’s partial survey of Newark Bay, NJ and the mouth of the Hackensack River, 1837.) The New Haven work was 1838. In 1839, the same Lt. Gedney and company captured the slave ship Amistad and brought the ship and captives to New Haven, claiming the escaped slaves as property. [UPDATE, 10/27/2016: Delving deeper into Gedney’s actions, it turns out he docked the ship in New London, while the captive Africans were brought to New Haven.] Then later, John Quincy Adams persuaded a judge they had freed themselves on the boat and were no longer slaves. 

Unzipping the files happened within an hour or so of getting an email from Michelle Zacks, a scholar of marine environmental history who has explored historic Coast Survey field survey notebooks as sources for her ongoing project on the antebellum oyster industry and the lives of enslaved and free African Americans in the Chesapeake region. That research helped lead to her new job, as the associate director of the Gilder Lehrman Center for the Study of Slavery, Resistance, and Abolition, at Yale, which is in: New Haven!

It all happened just like that!  Like the chart “wanted” to emerge back into the Amistad story.

We weren’t able to trace the origination of that zip file, but it was obviously created by someone who didn’t realize the value of the historical images. And this, ladies and gentlemen, is why we value historians.