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.

Online NOAA Custom Chart lets boaters create their own charts

A prototype version of a powerful new online tool, NOAA Custom Chart, is now available for boaters and other nautical chart users. The application enables users to define the scale and paper size of custom-made nautical charts centered on a position of their choosing. Once the functionality of this prototype is fully developed, NOAA Custom Chart will be an easy way for boaters to create a paper or digital back-up for the electronic chart system or other GPS-enabled chart display that they are using on board.

NOAA Custom Chart creates a geospatially referenced PDF (GeoPDF) from the NOAA electronic navigational chart (NOAA ENC®) database. In the final operational version of the application, chart notes and other margin notes will be placed at the bottom, below the chart neatline, similar to USGS topographic (US Topo) maps. The user may download, view, and print the output.

NOAA Custom Chart makes it easy for users to create a personalized chart.
NOAA Custom Chart makes it easy for users to create a personalized chart.

There are several options for customizing the appearance of the chart data. The prototype creates charts with either the “traditional” or “simplified” symbology of the Electronic Chart Display and Information Systems (ECDIS) used by professional mariners. Future versions of NOAA Custom Chart will add a full paper chart symbology option.

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Simple interface lets users choose a scale, paper size, and the center of their own chart.

If you are interested in customizing your own nautical charts, visit NOAA Custom Chart. Then tell us your ideas for improving it through NOAA’s Nautical Inquiry & Comment System. 

 

NOAA mobile integrated survey team prepares for hurricane season

NOAA’s Office of Coast Survey is the federal leader in emergency hydrographic response. Consecutive strong storms during the 2017 hurricane season made response efforts challenging, and emphasized the importance of having a well-trained and versatile staff. Coast Survey’s regional navigation managers, navigation response teams (NRTs), and mobile integrated survey team (MIST) worked with partners before and after the storms to quickly and safely reopen ports and waterways.

The MIST equipment is a mobile, quick-install side scan and single beam sonar kit that can be quickly set up on a vessel of opportunity. Recently, Coast Survey sent the MIST team to Astoria, Oregon to conduct a hydrographic survey of the Mott Basin area, which the U.S. Coast Guard (USCG) requested to confirm charted depth and obstruction data.

The MIST group used this as an opportunity to give NRTs experience with setup, usage, and tear down of MIST equipment, as well as to perform a system test prior to the upcoming hurricane season.

Data collection in the Mott Basin aboard the USCG Trailerable Aids to Navigation Boat (TANB) vessel
Data collection in the Mott Basin aboard the USCG Trailerable Aids to Navigation Boat (TANB) vessel

The team installed and integrated the MIST equipment on a USCG Trailerable Aids to Navigation Boat (TANB) vessel. TANB vessels are normally used for navigation aid maintenance, but can serve as a vessel of opportunity for hydrographic surveys using MIST equipment. During the 2017 hurricane season, NOAA used USCG vessels of opportunity in Florida and Puerto Rico for rapid hydrographic survey response.

Setting up the MIST equipment on a USCG TANB vessel
Setting up the MIST equipment on a USCG TANB vessel

The deployment to Mott Basin in not only provided USCG with hydrographic data to meet their operational mission, but also allowed NOAA to exercise equipment that will be critical to any upcoming storm or emergency response.

The MIST and USCG survey crew. Tim Wilkinson (NRT3, far left),Erin Diurba (NRT4, second from left), Alex Ligon (NRT1, second from right) and Mike Annis (HQ, far right) represented Coast Survey.
The MIST and USCG survey crew. Tim Wilkinson (NRT3, far left), Erin Diurba (NRT4, second from left), Alex Ligon (NRT1, second from right) and Mike Annis (HQ, far right) represented Coast Survey.

Coast Survey’s NRTs conduct hydrographic surveys to update NOAA’s suite of nautical charts. The teams are strategically located around the country and remain on call to respond to emergencies speeding the resumption of shipping after storms, and protecting life and property from underwater dangers to navigation.

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.).

NOAA navigation response team investigates hazardous shoal off Rockaway Point, NY

Recently, NOAA navigation response team 5 (NRT5), responded to a survey request from U.S. Coast Guard (USCG) Sector New York following several groundings near Rockaway Point in Queens, New York. Waves and currents often influence the size and shape of nearshore sandbars, and the USCG was concerned that a sandbar may have expanded beyond the area depicted on the nautical chart. Lt. j.g. Dylan Kosten, Eli Smith, and Michael Bloom traveled from New London, Connecticut, to Jersey City, New Jersey, to launch their vessel and start the survey of the area.

NRT5’s survey area around the large sandbar off Rockaway Point.
NRT5’s survey area around the large sandbar off Rockaway Point.

The location of the shoal and characteristics of the sandbar created challenging conditions for the survey team. In addition, the crew was asked to survey at a tighter contour (6-foot) than the standard 4-meter (13.1-foot) contour so that they could more clearly define the boundaries of the shoal. To fulfill this requirement, the crew of NRT5 took strong precautions to mitigate risks associated with surveying in shallow water with breaking waves and strong currents, and closely monitored conditions for changes throughout the day.

The shoal, located off Rockaway Point at the northern end of Raritan Bay, is exposed to both open ocean swells and strong tidal currents (left image, from surveyed area). The interaction of tides, currents, and waves surrounding the shoal produce rolling breakers (right photo). Wave energy stirs up the sediment and suspends large volumes of sand in the water column. Wave energy fluctuates as the tide ebbs and flows, and sand is washed away and deposited elsewhere – in this case, it formed a mostly permanent sand bar off of Rockaway Point.
The shoal, located off Rockaway Point at the northern end of Raritan Bay, is exposed to both open ocean swells and strong tidal currents (left image, from surveyed area). The interaction of tides, currents, and waves surrounding the shoal produce rolling breakers (right photo). Wave energy stirs up the sediment and suspends large volumes of sand in the water column. Wave energy fluctuates as the tide ebbs and flows, and sand is washed away and deposited elsewhere – in this case, it formed a mostly permanent sandbar off of Rockaway Point.

Conditions changed quickly. The northeast experienced unseasonably warm temperatures, and a thick blanket of fog engulfed New York Harbor as the warm air met the cold water of the ocean, harbors, and bays. With weather conditions thought to be better outside of the harbor and to likely improve later in the morning, the team cautiously transited to the project area and found conditions were indeed much more favorable.

Lt. j.g. Dylan Kosten keeping a steady watch through the thick fog.
Lt. j.g. Dylan Kosten keeping a steady watch through the thick fog.

Despite the challenges, NRT5 successfully completed the survey of the area by the end of the week. While the 6-foot contour was not reached in all areas due to breaking waves, the data was interpolated to that scale using lines of data run across the shoal in between wave sets. NRT5 has processed and analyzed the acquired data and Coast Survey will use it to create products to improve the resolution of the charted shoal and prevent future incidents.

During NRT5’s responses in areas surrounding the New York Harbor, the USCG Aids to Navigation Team (ANT) in Bayonne, New Jersey, offered the team a spot to dock their vessel at the end of the day. This sheltered station provided safety from poor weather conditions and allowed the team to quickly transit to project areas. Here, NOAA survey vessel S3007 is moored alongside at the USCG station.
During NRT5’s responses in areas surrounding the New York Harbor, the USCG Aids to Navigation Team (ANT) in Bayonne, New Jersey, offered the team a spot to dock their vessel at the end of the day. This sheltered station provided safety from poor weather conditions and allowed the team to quickly transit to project areas. Here, NOAA survey vessel S3007 is moored alongside at the USCG station.
Survey data coverage acquired around the sandbar. The black line marks the 12-foot depth contour and the red dashed line marks the interpolated 6-foot depth contour. The wreck symbols indicate where vessel groundings occurred in the weeks prior to this survey.
Survey data coverage acquired around the sandbar. The black line marks the 12-foot depth contour and the red dashed line marks the interpolated 6-foot depth contour. The wreck symbols indicate where vessel groundings occurred in the weeks prior to this survey.

Coast Survey’s NRTs conduct hydrographic surveys to update NOAA’s suite of nautical charts. The teams are strategically located around the country and remain on call to respond to emergencies speeding the resumption of shipping after storms, and protecting life and property from underwater dangers to navigation. NRT5 team members contributed the content of this story.

NOAA ships Fairweather and Rainier mark 50 years of service and survey

 

NOAA ships Rainier and Fairweather.
NOAA ships Rainier (left) and Fairweather (right) alongside at Marine Operations Center – Pacific in Newport, Oregon.

To recognize the successful history of NOAA ships Fairweather and Rainier, as well as the professional mariners, hydrographers, and commissioned officers who have served aboard these ships for the last 50 years, NOAA hosted a ceremony and public ship tours at the Marine Operations Center – Pacific (MOC-P) in Newport, Oregon.

The ceremony opened with the national anthem sung by Ensign Airlie Picket and HAST Amanda Finn. Capt. Keith Roberts, commanding officer, Marine Operations Center – Pacific, served as master of ceremonies introducing Representative David Gomberg, District 10 – Central Coast Oregon State Legislature, Rear Adm. Shep Smith, director, Office of Coast Survey, and Rear Adm. Nancy Hann, deputy director, Office of Marine and Aviation Operations and NOAA Corps, who all gave remarks during the ceremony.

“Today we are here to recognize a milestone in the career of the Rainier and Fairweather, who turn 50 this year.  They are the last of a generation of truly beautiful ships,” said Rear Adm. Shep Smith. “The passion, dedication, and craftsmanship of generations of engineers and deck force have kept these ships operable for 50 years and this is no small feat.”

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Past and present crew of NOAA ships Fairweather and Rainier.

Rear Adm. Hann provided comments on the hydrographic fleet’s contribution to the national economy and the importance of investing in the future of NOAA’s fleet. “There is recognition in the value of the work that the crew of the Rainier, Fairweather, and the entire NOAA fleet provides to the nation.”

NOAA Teacher at  Sea Alumni Association presented plaques honoring the ships to their commanding officers, Cmdr. Mark Van Waes and Cmdr. Ben Evans. The ceremony closed with the commanding officers of both ships directing inspirational words to their crews.

NOAA Teacher at Sea Alumnus Lisa Battig presents a plaque honoring NOAA Ship Fairweather to Cmdr. Mark Van Waes, commanding officer of the ship (left). NOAA Teacher at Sea Alumnus Denise Harrington presents a plaque honoring NOAA Ship Rainier to Cmdr. Ben Evans, commanding officer of the ship (right).
NOAA Teacher at Sea Alumnus Lisa Battig presents a plaque honoring NOAA Ship Fairweather to Cmdr. Mark Van Waes, commanding officer of the ship (left). NOAA Teacher at Sea Alumnus Denise Harrington presents a plaque honoring NOAA Ship Rainier to Cmdr. Ben Evans, commanding officer of the ship (right).

Following the ceremony, NOAA hosted over 400 members of the public on ship tours and tours of the MOC-P museum, a collection that features several of NOAA’s heritage assets. Visitors had the opportunity to board the ships, speak with the crew, and explore one of the many launches (small boats) that the ships deploy to conduct hydrographic survey operations.

ENS Airlie Picket shows visitors how to map the seafloor using sounding boxes.
Ensign Airlie Picket shows visitors how to map the seafloor using sounding boxes.
NOAA Ship Rainier and visitors.
Visitors of all ages toured NOAA ships Rainier and Fairweather during the open house at MOC-P.

Both ships, along with their sister ship, Mt. Mitchell, were constructed at the Jacksonville Shipyards in Florida and later christened in March of 1967. Following hydrographic tradition, the ships were named for features near their working grounds—Alaska’s Mt. Fairweather, Washington’s Mt. Rainier, and North Carolina’s Mt. Mitchell. The U.S. Coast & Geodetic Survey commissioned the Fairweather and Rainier in October of 1968 at the Pacific Marine Center in Seattle. Mt. Mitchell was launched one year earlier and, though no longer commissioned with NOAA, is still operating as a privately-owned research vessel.

NOAA ships Fairweather, Rainier, and Mt. Mitchell under construction.
NOAA ships Fairweather, Rainier, and Mt. Mitchell were built in the Jacksonville Shipyard in Florida.

 

NOAA Ships Fairweather and Rainier .
NOAA Ships Fairweather and Rainier were christened in Jacksonville, Florida, in March, 1967.

The NOAA ships are operated and maintained by the Office of Marine and Aviation Operations, with hydrographic survey projects managed by the Office of Coast Survey. NOAA thanks the U.S. Coast and Geodetic Heritage Society and the National Marine Sanctuary Foundation for their support of this event.

NOAA quickly updates nautical chart, allowing large ships to dock with confidence in Port Everglades

NOAA’s Office of Coast Survey quickly updated NOAA electronic navigational charts (NOAA ENC®) to accurately reflect the 225 foot expansion of a slip in Port Everglades, Florida. Now at a total length of 1,125 feet, the elongated slip allows larger ships to dock with confidence. The Port Everglades Pilots – maritime pilots who maneuver ships through crowded harbors and confined waters – requested the chart update. With ENCs that accurately reflect the slip expansion in their hands, pilots can easily communicate to vessel captains that it is safe to dock their vessels in the slip.

Port Everglades is one of the top three cruise ports in the world, and is among the most active cargo ports in the United States. Every slip is kept in high use, and Coast Survey used a new data process that allowed the most critical and valuable information to be applied quickly and made available to the end user.

To update nautical charts, Coast Survey historically applied data that covered the entire shoreline. This process was cumbersome and time-consuming as updates were based on a print (not digital) cycle. However, in this case, Coast Survey utilized discrete shoreline snippets of the target areas, provided by National Geodetic Survey’s Remote Sensing Division (RSD), to ensure a quick turnaround of the corrected charts.

The 190-meter bulk carrier "Port Shanghai" using the recently extended portion of Slip 2 before the ENC was updated (left image), making it appear as though the vessel bow has grounded. After the ENC update, the change in the slip length was reflected in ENC cell US5FL32 and US4FL31 (right image). Credit: NOAA
The 190-meter bulk carrier “Port Shanghai” using the recently extended portion of Slip 2 before the ENC was updated (left image), making it appear as though the vessel bow has grounded. After the ENC update, the change in the slip length was reflected in ENC cell US5FL32 and US4FL31 (right image). Credit: NOAA

Harbor bathymetric survey data from the U.S. Army Corps of Engineers and shoreline revision data from a georeferenced WorldView-2 image, compiled by the RSD, were used to update the harbor (1:10,000) and approach (1:80,000) ENC charts. This ENC-first, digital structure as outlined in the National Charting Plan helps Coast Survey quickly apply updates to charts, increase efficiency, and streamline data workflows.