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.”


“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



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.

A monumental history

On September 15, 2016, President Obama designated the first marine national monument in the Atlantic Ocean. The Northeast Canyons and Seamounts Marine National Monument includes two areas: one that includes four undersea mountains, called “seamounts” – Bear, Mytilus, Physalia, and Retriever; and an area that includes three undersea canyons – Oceanographer, Lydonia, and Gilbert – that cut deep into the continental shelf. These sea features have monumental histories.

Monuments map, by Leland Snyder, Office of Coast Survey
Coast Survey cartographer Leland Snyder used several data sources to create this map of the Northeast Canyons and Seamounts Marine National Monument.


Bear, Mytilus, and Physalia Seamounts were discovered by oceanographers with Woods Hole Oceanographic Institution, and they were named for small Woods Hole vessels that began making forays into the deep sea in the 1950s. The Bureau of Geographical names does not know the origin of the name “Retriever Seamount,” but NOAA historian Skip Theberge thinks it was probably discovered and named for the Cable Repair Ship Retriever, which started service in 1961 working off the East Coast. The canyons were named in the 1930s, for U.S. Coast and Geodetic Survey ships. (C&GS is the earliest NOAA predecessor agency.) Oceanographer Canyon was named for the C&GS Ship Oceanographer, which discovered many canyons incising the continental slope between the Georges Bank area and Cape Hatteras; Gilbert Canyon was named after the C&GS Ship Gilbert, which took an active part in the survey of the Georges Bank, 1930-32; and Lydonia Canyon was named for the C&GS Ship Lydonia.

The monument, which encompasses 4,913 square miles, has been the subject of scientific exploration and discovery since the 1970s. But the original discoveries of the canyons were made more than 80 years ago, when the U.S. Coast and Geodetic Survey surveyed the canyons with TNT bombs.

Yes, you read that right.

Some of the C&GS ships in the 1930s were anchored-station vessels, hanging a hydrophone over the side at a well-determined point. TNT bombs were thrown over the sides at about fifteen minute intervals. The explosion being “time zero,” the sound waves traveled through the water to the hydrophone, which in turn activated an automatic radio signal back to the survey vessel. The time interval between reception of radio signal and time of explosion, times the velocity of sound in sea water, gave the distance. This system, called “radio-acoustic ranging,” was developed by C&GS as the first non-visual survey system.

The survey of these canyons, using (for then) modern methods gave an unprecedented view of the seafloor generating debates as to the cause of the canyons, and in a larger sense, generating the birth of marine geology. Indeed, Dr. Francis Shepard, recognized by many as the “father of marine geology,” got his start on these surveys.

This excerpt from International Aspects of Oceanography, a National Science Foundation publication, was written by Wayland Vaughn of the Scripps Institution of Oceanography in 1937. He describes the contribution of both echo-sounding and the navigation system termed "radio-acoustic ranging" to the mapping of the seafloor. C&GS developed RAR and used it to survey U.S. continental margins in the 1930s.
This excerpt from International Aspects of Oceanography, a National Science Foundation publication, was written by Wayland Vaughn of the Scripps Institution of Oceanography in 1937. He describes the contribution of both echo-sounding and the navigation system termed “radio-acoustic ranging” to the mapping of the seafloor. C&GS developed RAR and used it to survey U.S. continental margins in the 1930s.


The history of these early explorations is fascinating. So as not to give it short shrift, we are going beyond our normal blog post format and including a full-length article contributed by NOAA’s historian, retired Capt. Skip Theberge.

♦ ♦ ♦

A History of Exploration and Discovery in the Northeast Canyons and Seamounts Marine National Monument

By Capt. Albert “Skip” Theberge,  Jr., NOAA (retired), Acting Chief of Reference, NOAA Central Library

The recent designation of the Northeast Canyons and Seamounts Marine National Monument is the culmination of over eighty years’ involvement in this area by NOAA and its predecessor agencies. It is no accident that the canyons in this area were named for ships of the U.S. Coast and Geodetic Survey (C&GS), NOAA’s oldest ancestor agency. Oceanographer, Gilbert, and Lydonia Canyons were named for three of the four ships that conducted surveys of the area between the years 1930 and 1932. The fourth ship, Welker, is commemorated by the naming of Welker Canyon, just to the west of the new monument boundaries, and a fifth ship, Hydrographer, was commemorated by the naming of the next canyon to the west of Welker Canyon.  These ships completed the first comprehensive survey of the continental slope in this area, using the most modern equipment available: a combination of advanced echo-sounding equipment and the radio-acoustic ranging system, the first survey-quality non-visual navigation system. This system was developed in the Coast and Geodetic Survey.

C&GS map of submarine valleys on Georges Bank, 1932
C&GS map of submarine valleys on Georges Bank, 1932


Besides being used for navigational charts, the data from these surveys was used in a number of scientific publications, first by Francis Shepard, known as the father of marine geology. Although going on to become a famous Scripps Institution of Oceanography scientist, some of his earliest work was initially published in the Bulletin of the Field Engineers of the Coast and Geodetic Survey. However, the greatest work associated with these surveys was a paper published in 1939 by the geologist A.C. Veatch and the brilliant C&GS officer Lieutenant Paul Smith. This paper was titled “Atlantic Submarine Valleys of the United States and the Congo Submarine Valley” and was Geological Society of America Special Papers Number 7. Included in this paper was a beautiful map that extended from Lydonia Canyon on its northeast corner to Norfolk Canyon off Chesapeake Bay at its southern limit. Shown on this map were thirteen named canyons as well as a number of other canyons incised in the continental shelf.

Veatch and Smith bathymetic map
This famous Veatch and Paul Smith bathymetric map from 1939 generated an ongoing interest in marine geology by showing that the seafloor was not dull and featureless.


This map served to call the attention of the geological community to the rugged and grand nature of the seafloor, previously believed by many to be bland and featureless. It also served to ignite a fierce debate in the scientific community regarding the mode of formation of canyons. There were two competing theories. The first theory was that the canyons formed sub-aerially with sea level dropping as much as 10,000 feet worldwide. The second theory was that sediment-laden density currents carved out the canyons. Both theories had influential backers but, ultimately, as a result of Woods Hole Oceanographic Institution (WHOI) sediment sampling in the early 1950s on the oceanic extension of Hudson Canyon, the density current theory won out as layers of poorly graded sands and gravels were found far at sea. This, combined with knowledge of the sequential breaking of further downslope submarine cables over a period of 13 hours following the 1929 earthquake on the Grand Banks, served to prove the concept of density currents.

The Second World War brought new studies in this area as the continental shelf and slopes of the United States were the locus of fierce submarine warfare. Woods Hole Oceanographic Institution and the Coast and Geodetic Survey combined efforts to map the location of known shipwrecks and bottom sediment types on a series of charts extending from east of Georges Bank to the tip of Florida. This was not WHOI’s first work in the area, as Maurice Ewing had conducted early seismic reflection and refraction experiments in this area before the war.

Chart 1107-A in 1943
C&GS issued chart 1107-A in 1943, showing names of canyons. This was a restricted chart (used in anti-submarine warfare) overprinted with bottom characteristics and known shipwrecks.


Following the war, WHOI sent numerous expeditions into the Atlantic and discovered three of the seamounts included in the Northeast Canyons and Seamounts National Marine Monument. These three were Bear, Mytilus, and Physalia and were named for small inshore vessels operated by WHOI. Although the earliest mention of these seamounts in the unclassified literature was in 1962, John Ziegler of WHOI first discovered and named these features in 1955 on a classified survey. A prototype Heezen-Tharp physiographic diagram that was probably produced in the mid-1950s clearly shows the New England Seamount Chain and seamounts in the vicinity of the three Woods Hole seamounts of the monument.  The fourth seamount in the monument, Retriever Seamount, was probably discovered by and named for the cable repair ship Retriever which operated off the east coast of the United States in the early 1960s.

Geological discovery and interpretation of the canyons and seamounts dominated research until the late 1960s. At this time, studies began of the dynamic oceanography of Oceanographer and other New England canyons. The first manned submersible dives into the canyon also occurred at this time, with 1966 Alvin dives followed in 1972 and 1974 by dives in the Navy’s nuclear research submersible NR-1. Oceanographer Bruce Heezen was aboard and suggested a “balanced concept in which canyons are created by some tectonic forces or drowned river valleys, are shaped and kept alive by the tides and are coursed by turbidity currents at certain long term intervals when especially large supplies of sediment are delivered to the heads of their system.” In the late 1970s and early ‘80s, there were sporadic efforts to begin studying the biology of the canyon systems, which has continued up to the present day. Since 2000, there has been a significant increase in studies related to these systems. The first dive on a seamount of the new monument was made on July 24, 1968, on Bear Seamount, by K. O. Emery in the submersible Alvin. Minimal information was obtained, but in 1974 a series of dives was made from the vicinity of Corner Seamount to Mytilus Seamount under the direction of James Heirtzler as chief scientist. In his words, this was the first time that “man had directly viewed the expanse of the earth between the Mid-Atlantic Ridge and the North American continent.” Dive 7, the final dive, was made on Mytilus Seamount; it was described as “unique” as it is capped by approximately 300 meters of shallow water reef material. As this occurs at a depth of over 3,000 meters, it is apparent that this seamount has subsided over two miles while being rafted to the northwest from its original location over the Great Meteor hotspot.

Biological studies of these seamounts did not begin in earnest until 2000, when NOAA Ship Delaware II made 20 exploratory trawls in the vicinity of Bear Seamount. Over 270 species were collected including 115 fish species, 26 cephalopod species, and 46 crustacean species. Over the next thirteen years, NOAA’s Office of Ocean Exploration and Research (OER) followed up the fisheries cruise with a number of expeditions to the vicinity of the newly designated national monument. The first of these cruises was the 2003 Mountains in the Sea Expedition which, following in the footsteps of Heirtzler years earlier, used the submersible Alvin to dive on Manning and Kelvin seamounts and conduct multibeam surveys of Bear Seamount. As opposed to the primarily geologic emphasis of the earlier dives, though, these concentrated on the remarkable biological diversity of the New England Seamount Chain. This expedition was followed by Mountains in the Sea 2004, in which the use of robotic vehicles instead of a manned submersible was used to conduct explorations. 2004 saw Retriever, Balanus, and Bear Seamounts explored and the acquisition of hundreds of spectacular photos of the seafloor. 2005 saw the North Atlantic Stepping Stones expedition which, although not studying seamounts in the national monuments, did explore a number of seamounts of the New England Chain. In 2012, NOAA ocean exploration ship Okeanos Explorer returned to the northeast continental shelf and slope area on the Northeast and Mid-Atlantic Canyons mapping expedition. This expedition was primarily concerned with multibeam mapping of the various canyons, including those in the monument, as preparation for the 2013 Northeast U.S. Canyons Expedition that investigated Oceanographer, Lydonia, and Gilbert Canyons, other large canyons of the regions, and Mytilus Seamount. This expedition marked the first use of NOAA’s 6,000 meter-rated remotely operated vehicle, Deep Discoverer and its accompanying Seirios camera sled which enabled telepresence ocean exploration. With this technology, OER was able to provide scientific and public audiences onshore a real-time view of ocean discovery in the grand canyons and hidden mountains of our Atlantic Ocean frontier.

Over eighty years of discovery and exploration, much of it accomplished by NOAA, its predecessor agencies, and academic partners have led to President Obama’s presidential proclamation of the Northeast Canyons and Seamounts Marine National Monument. The monument will assure that the unique ecosystems of this fragile area will be protected for posterity.

Four Gulf of Mexico basins named for officers who led EEZ bathymetric mapping

The U.S. Board on Geographic Names recently named four previously unknown basins in the United States Exclusive Economic Zone (EEZ) in the Gulf of Mexico, honoring retired NOAA officers who mapped the area in the late 1980s and early 1990s. The names — Armstrong Basin, Floyd Basin, Matsushige Basin and Theberge Basin — were proposed by Texas A&M University, based on their new compilation of bathymetry drawn largely from the NOAA multibeam mapping project conducted by now-decommissioned NOAA ships Whiting and Mt. Mitchell.

Newly named Armstrong Basin
A basin in the Gulf of Mexico was named after retired NOAA Captain Andrew Armstrong.


Retired NOAA Capt. Richard P. Floyd was the commanding officer of NOAA Ship Whiting from February 1990 to March 1992; he was followed by retired Capt. Andrew A. Armstrong III, who was CO from February 1992 to January 1994. Retired NOAA Capt. Roy K. Matsushige was commanding officer of NOAA Ship Mt. Mitchell from December 1988 to January 1991, followed by retired Capt. Albert E. Theberge, who served as CO from January to November 1991. The officers led the bathymetric mapping operations under the direction of NOAA’s Office of Charting and Geodetic Services, a predecessor of today’s Office of Coast Survey.

Cartographers rely on the Board of Geographic Names, for good reason!

Since 1890, federal cartographers have relied on the decisions of the U.S. Board on Geographic Names — the 125-year multi-agency federal program to standardize names of geographic features — that operates under the umbrella of the Department of the Interior.

“The Board on Geographic names has its intellectual roots in the earliest map-making efforts,” explains Theberge. To illustrate the need for standardization in the U.S., Theberge points to a November 7, 1805, report by the famed explorer William Clark.

“Ocian in view! O! the joy… Great joy in camp we are in view of the Ocian, this great Pacific Octean which we been So long anxious to See.”

As Theberge points out: “In one sentence, Clark gives the reasons for the Board.”

EEZ mapping project achieved policy and technical objectives for U.S.

The four NOAA commanding officers led surveys for the EEZ mapping project, which was active between 1984 and 1991. The project originated from President Ronald Reagan’s 1983 proclamation establishing a U.S. Exclusive Economic Zone, which created a 200-mile-wide nautical “belt” around the U.S. and territories, adding over 3,000,000 square nautical miles to the nation’s jurisdiction.

In response to the EEZ proclamation, both NOAA and the United States Geological Survey embarked on mapping programs. The USGS used a deep-water, very wide swath, side scan sonar system called GLORIA, which gave a qualitative picture of the seafloor somewhat akin to aerial photography; and NOAA used both medium depth multibeam sounding systems (150 meters to 1000 meters) and deep water systems (1000 meters depth to full oceanic depth), which gave quantitative (depth) values. As opposed to widely-spaced single beam trackline in deep water areas, NOAA’s program attained 100% bottom coverage with the then-new (to the civil community) multibeam systems.

The Gulf of Mexico was one region of the mapping program, as maps were produced for waters of the East Coast, Gulf of Mexico, West Coast, Alaska, and Hawaii. In a paper presented at the 1988 Exclusive Economic Zone Symposium, the goals of mapping in the Gulf of Mexico (actually applicable to all EEZ regions) were espoused:

  • Build the foundation of a marine environmental geographic information system for solving global and regional change problems.
  • Improve targeting of scientific and engineering efforts involving higher-cost, manned, submersible investigations and remotely-operated vehicle operations.
  • Better manage the living and mineral resources of the EEZ.
  • Better model the physical oceanography of the Gulf of Mexico, including factors affecting water mass movements, acoustic propagation paths, and sediment transport regimes.
  • Model geological and geophysical hazards affecting coastal regions and offshore construction.
  • Discover and/or define unique or previously unknown marine environments for designation as marine sanctuaries or protected areas.
  • Improve and enhance nautical charts and bathymetric maps.

This early multibeam mapping effort helped develop many concepts that Coast Survey later built on in shallow water multibeam charting, such as methods for correcting and calibrating beam pointing errors, use of GPS, ray-bending algorithms to account for refraction of beams, etc. Philosophically, the project also helped pave the way for the era of digital paperless survey data acquisition and processing, as EEZ survey operations significantly reduced the vast amounts of paper fathograms, printouts, and other products that accompanied classical hydrographic survey operations.

In 1992, a report by the Marine Board of the National Research Council addressed the needs of mapping the EEZ. It noted:

“EEZ mapping and survey activities of the USGS and NOAA have been impressive, especially given the limits on funding, assets, and human resources. …The current activities depend on individual efforts and assets that are, in many instances, borrowed or diverted from other projects.”

By the time the report was written, circumstances — including the grounding of the Queen Elizabeth II in Martha’s Vineyard Sound — dictated that NOAA devote more resources to inshore charting. The EEZ project was terminated but it left a legacy of new and improved methods, as well as a gentle nudge towards a paradigm shift from primarily paper data acquisition to digital data acquisition.

We still use the digital data gathered by the EEZ mapping project. During the monitoring of the Deepwater Horizon oil spill, NOAA used the data as its underlying bathymetric dataset. The spill was near Whiting Dome and Mitchell Dome, which were named respectively for their discovery by the NOAA ships Whiting and Mt. Mitchell during the EEZ project.

New project picks up where the EEZ project left off

Today, a new national deep-water bathymetric mapping project is underway, picking up where the EEZ project left off. The Office of Coast Survey’s Joint Hydrographic Center at the University of New Hampshire, along with NOAA’s Office of Ocean Exploration, is leading the bathymetric mapping work of the interagency U.S. Extended Continental Shelf (ECS) Project. Using today’s modern high-resolution descendants of the multibeam systems aboard Whiting and Mt. Mitchell, the ECS Project the ECS Project is mapping the continental slope in several regions, including the Gulf of Mexico, to establish the outer limits of the U.S. continental shelf in areas beyond the 200 nautical mile EEZ. Andy Armstrong, of recently named Armstrong Basin fame, continues to use his bathymetric mapping expertise, now conducting mapping operations for the ECS Project.