NOAA and Coast Guard survey shallow channels in eastern Chesapeake Bay to update aids to navigation

By Lt j.g. Patrick Debroisse

The area of the Chesapeake Bay along the Eastern Shore of Maryland is one of our nation’s treasures. Home to unique underwater grasses, fish, and shellfish, this complex transition from river to sea is also home to millions of tons of sediment delivered annually from eroding land and streams. Recreational boaters, fisherman, and cruising vessels are keenly aware of the shifting sands and sediment deposits in these shallow waters and rely on aids to navigation (ATON) — a system of beacons and buoys — to travel safely to and from the harbors and docks along the shoreline.

U.S. Coast Guard (USCG) Aids to Navigation Team (ANT) from Crisfield, Maryland, recently requested the assistance of NOAA’s Office of Coast Survey to help identify areas where ATON were in need of repair, relocation, or removal due to the shifting sediment of these nearshore areas. Crew from NOAA research vessel Bay Hydro II and from navigation response team (NRT) 1 (homeported in Stennis, Mississippi) operated an Echoboat autonomous surface vehicle (ASV) from a USCG vessel to survey these shallow waters. 

Lt j.g. Patrick Debroisse readies the Echoboat ASV for hydrographic survey
Lt j.g. Patrick Debroisse (NOAA, junior officer in charge, Bay Hydro II) readies the Echoboat ASV for hydrographic survey in the nearshore waters of the Chesapeake Bay.
Alex Ligon (NOAA NRT1) works with USCG Boatswain Mate (BM) 1 Lee Durfee, BM2 Collin Blugis, and Machinery Technician 3 Matt Kemp to load the ASV on the USCG vessel.
Alex Ligon (NOAA, NRT 1) works with USCG Boatswain Mate (BM) 1 Lee Durfee, BM 2 Collin Blugis, and Machinery Technician 3 Matt Kemp to load the ASV on the USCG vessel.

The team first visited Slaughter Creek, near Taylor’s Island, where the USCG believed sediment in the channel was shifting, requiring potential ATON relocation. The second area was in Pocomoke River, east of Smith Island, where shoaling in the already shallow channel was of concern, as well as the existence of unused ATON anchors. The ASV, equipped with side scan sonar to search for underwater objects, and a multibeam echo sounder to check the contours of the channels, surveyed both areas.

Once the survey data is processed and delivered to the USCG ANT, they can make informed decisions about ATON maintenance. Finding old ATON anchors and recycling them back into service is a potential cost savings for the USCG. NOAA and the USCG plan to operate the Echoboat ASV in this area again, surveying the waters for a possible wreck in Fishing Bay and for old ATON moorings replaced by a day shape.

Echoboat ASV surveys in the Pocomoke River Channel to investigate possible shoaling.
Echoboat ASV surveys in the Pocomoke River channel to investigate possible shoaling.
Alex Ligon (NOAA NRT 1) watches the ASV data in real-time. The ability to watch the data real time allows real-time decision making for survey planning and preliminary products to be provided to the Coast Guard ANT.
Alex Ligon (NOAA, NRT 1) watches the ASV data in real-time, which allows for real-time decision making for survey planning and preliminary products.

Coast Survey recently surveyed the waters of Lake Champlain using the Echoboat ASV.  This portable unit provides flexibility and allows survey teams to further develop procedures and to train more individuals in its use for future operations around the country.

Crew of NOAA Ship Rainier surveys Everett, Washington, to update charts

By Lt. j.g. Michelle Levano
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RA-6 in Elliott Bay, downtown Seattle. Photo Credit: Lt. Andrew Clos

As NOAA Ship Rainier underwent repairs in South Seattle, the ship’s survey launches and their crews carried out a project to update nautical charts around the Port of Everett and its approaches in Possession Sound. The boats used state-of-the-art positioning and multibeam echo sounder systems to achieve full bottom coverage of the seafloor.

The ports of Seattle, Tacoma, and Everett have experienced an increase in vessel traffic and capacity within the last decade. The Port of Everett serves as an international shipping port bringing jobs, trade, and recreational opportunities to the city. Across Possession Sound, Naval Station Everett is the homeport for five guided-missile destroyers, and two U.S. Coast Guard cutters. The data collected from this project will support additional military traffic transiting to and from Naval Base Kitsap in addition to the Washington State Ferries’ Mukilteo/Clinton ferry route, commercial and tribal fishing, and recreational boating in the area.

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From left to right: Hydrographic Senior Survey Technician (HSST)  Barry Jackson, Hydrographic Assistant Survey Technician (HAST) Amanda Finn, HSST Gregory Gahlinger, HAST Jonathan Witmer, Able Bodied Seaman Tyler Medley, HAST Carl Stedman, Lt. j.g. Michelle Levano, NOAA, and Lt Andrew Clos, NOAA, in Everett at the start of the project. Photo Credit: Lt. j.g. Michelle Levano

Some areas of the charts outside of Everett are based on data acquired between 1940 and the 1960s, a time when sonar technology did not allow acquisition of full bottom coverage. Complete multibeam coverage will provide mariners with modern, highly accurate information on shoals, rocks, and intertidal mudflat locations. During the first week of May, a team of nine Rainier crew members moved four survey launches from Lake Washington, where Rainier was docked, to Everett. The team, consisting of wardroom, survey, and deck department members, conducted 17 days of survey.

During this project, Rainier trained several individuals to become qualified hydrographers in charge and/or launch coxswains. Much of the multibeam acquisition in the Everett project was more gradual and shallow compared to the “steep and deep” coastline of Alaska that Rainier is more accustomed to seeing. This served as a perfect place for individuals to increase confidence and capability after a long winter repair period.

In addition to updating depth data, the Rainier survey team updated chart symbology information found on paper and electronic navigational charts of the area. Some examples of chart symbology include rocks, kelp beds, aids to navigation, traffic separation schemes, and other man-made and natural features. Traditionally, chart features are positioned using the ship’s 19-foot outboard skiffs. Equipped with a GPS positioning unit, the skiffs carefully approach a charted or new feature, and get as close as safely possible to determine the location and height. The Port of Everett contains many man-made shoreline features such as pilings, docks, and breakwater which are ideal for using a topographic laser to collect feature attribution.

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HSST Barry Jackson, HAST Jonathan Witmer, and Lt. Andrew Clos, NOAA, take RA-2 out for maneuvering training before starting the laser. Photo Credit: HAST Carl Stedman

For this project, the team used Rainier’s relatively new jet-propelled boat, RA-2, that is equipped with lidar. Using sixteen laser beams, light reflects off an object and is detected by a receiver; similar to how the sonar is used to find objects on the seafloor. Topographic laser feature attribution allows the surveyor to locate and place these features accurately with height information combined with precise positioning and orientation (roll, pitch, and yaw of the vessel) data.

The crew to gained experience and developed procedures using laser technology for feature positioning and height, which is safer for the crew than previous collection methods. Now, survey crews can collect highly accurate feature information from a distance. This experience, training, and procedure development was an important component of preparation for upcoming fieldwork in Alaska where the rocky and rugged Alaskan coastline experiences a large tidal range and contains many features that must be correctly identified and positioned. Rainier’s survey team received support on this project from NOAA’s Office of Coast Survey’s Hydrographic Systems and Technologies Branch, which provided additional training on lidar use and data processing.

Stay tuned for future Rainier survey updates as she heads north to survey Tracey Arm outside of Juneau, Alaska, and the ship’s adventures in California later this summer!

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Area surveyed for approaches to Everett.

Rainier would like to thank the Port of Everett for accommodating the ship’s launches throughout the duration of this survey project.

NOAA surveys Lake Champlain for improved flood modeling and mitigation strategies

At the request of the NOAA Great Lakes Environmental Research Lab (GLERL), NOAA’s Office of Coast Survey deployed a survey team and a new autonomous surface vehicle (ASV) to gather hydrographic data in and around the narrow causeway inlets that dot the Lake Champlain basin in Vermont. GLERL will use the data to improve flood forecast models and analyze flood mitigation strategies in the Lake Champlain-Richelieu River system as part of a U.S. and Canada study led by the International Joint Commission.

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Navigation response team (NRT) members watch from the launch vessel as a new autonomous surface vehicle, the Echoboat, surveys shallow waters in Lake Champlain. The Coast Survey team included Mike Annis from headquarters and Alex Ligon and Josh Bergeron from NRT1 (Stennis, Mississippi) to support the ASV operations, as well as Lt. j.g. Dylan Kosten, Eli Smith, and Michael Bloom of NRT5 (New London, Connecticut) to provide additional support.

Lake Champlain drains northward to the St. Lawrence River (via the Richelieu River) and is part of the Great Lakes system. In 2011, the lake reached record water levels due to large amounts of spring precipitation, snowmelt, and runoff. This water caused more than 60 consecutive days of severe flooding that affected thousands of U.S. and Canadian residents.

To gather hydrographic data that will improve lake modeling and forecasting going forward, a Coast Survey navigation response team (NRT) deployed a Seafloor Systems Echoboat to survey areas of the basin that are too shallow for traditional survey vessels to reach. In this way, the ASV acted as a force multiplier to the NRT survey vessel. Coast Survey acquired the Echoboat earlier this year, and it is Coast Survey’s first ASV to be equipped with multibeam sonar—the same type of sonar that larger NOAA survey vessels use to gather high resolution hydrographic data. With the use of this technology, the data gathered by the ASV system may be included on NOAA navigational products.

 

Video: The new autonomous surface vehicle, the Echoboat, surveys shallow waters in Lake Champlain. 

 

This was the inaugural operational use of the Echoboat, and allowed the team to gain experience setting up, running, and maintaining the ASV. Identifying and addressing software and hardware issues now prepares the team for future deployments.

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Survey data of a causeway in Lake Champlain collected by the ASV (in the green polygon) and the NRT survey vessel.

Prior to the survey, much of the hydrographic data for Lake Champlain was well over 100 years old and of sparse density. Developers at GLERL needed more detailed hydrographic information in several shallow water areas in the northern sections of the lake to complete hydrodynamic models. Lake Champlain is a complex system populated with islands spread across multiple basins, many of which are connected by bridges and causeways. Critical to the flow of water between the different basins of the lake are multiple narrow, shallow inlets bisecting these causeways. The survey dataset Coast Survey delivered to GLERL is key to knowing the volume of water that flows through these bottlenecks in order to model circulation, water levels, and the resulting floods in the lake.

Coast Survey spotlight: Meet Starla Robinson


Ever wonder what it’s like to be a member of the NOAA Coast Survey team? We will use the Coast Survey spotlight blog series as a way to periodically share the experiences of Coast Survey employees as they discuss their work, background, and advice.


Starla Robinson, Physical Scientist

“The work we do has real value and every sounding takes a team of professionals from multiple disciplines. I like being a part of something greater.”

Starla Robinson served as a crew member on the NOAA Ship Rainier. Photo credit: Lt. Damian Manda, NOAA Corps
Starla Robinson served as a crew member on NOAA Ship Rainier. Photo credit: Lt. Damian Manda, NOAA Corps
What were your experiences prior to working for NOAA Office of Coast Survey?

I worked a decade as a GIS Analyst and then four years as a Survey Technician on NOAA Ship Rainier. I have been working as a Physical Scientist for Coast Survey for three years, and in this position I plan hydrographic surveys.

What is a day in your job like?

Varied. I am a project manager. My responsibility is to plan surveys, identify risks and opportunities, and see the surveys through completion. I spend time on land researching existing data, analyzing opportunities, facilitating communication, and defining plans. Once a project is started I assist in answering questions, monitoring progress, and communicating the value of what we do.

I also have the great privilege to sail on our ships as both a project manager and survey crew. At sea I act as a liaison to land, maintain my skills, experiment with new methods, and stand a survey watch. Working on a ship allows me to see things that very few people get to see. We are explorers in a strange land, uncovering an environment no one has seen before.

Why is this work important?

Project managers are the opportunity makers and the communicators that stitch the team together for the execution of the surveys that maintain the nation’s charts. We get to be the experts, defining the requirements for national hydrography, and safeguarding quality, while making sure we effectively manage the taxpayer’s resources.

What aspects of your job are most rewarding to you?

I work with teams of brilliant, dedicated professionals who are passionate about our work. Our work provides me with a sense of purpose. I know the importance of our data to mariners. I have been in a ship looking for safe harbor. I know the importance of our data to commerce, fisheries, habitat analysis, offshore energy, sand mining, and resource management. I use my expertise in hydrography and GIS to answer questions and strategize for the future. The work we do has real value and every sounding takes a team of professionals from multiple disciplines. I like being a part of something greater.


We are celebrating World Hydrography Day all week! Check our website to see new hydrography- and bathymetry-related stories added each day.

From seaports to the deep blue sea, bathymetry matters on many scales

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By Rear Adm. Shep Smith, Director of the Office of Coast Survey

On Thursday, June 21, we celebrate World Hydrography Day. This year’s theme—Bathymetry – the foundation for sustainable seas, oceans and waterways—is very timely as many hydrographic organizations worldwide are focusing on bathymetry at local and global scales. While we work to perfect real-time data and high-resolution bathymetry for ports, we are still working to build a foundational baseline dataset of the global seafloor. Our work at both scales have implications for the local and global economies.

Let me start with the global seafloor. For the untrained eye, particularly those looking at a Google Earth image, it would appear that the monumental task of mapping the seafloor is accomplished. Geologic features appear detailed under a deep sea of blue. Little do most people know, however, that the majority of this surface is interpolated. In other words, we do a good job filling in the blank spaces between the sparse depth measurements we have. This creates a pretty picture, but does not provide valuable and much needed data for resource management, offshore energy planning, mineral extraction, and other fields of research that require high-resolution data to do meaningful work and build on existing scientific knowledge. In fact, the United Nations proclaimed a Decade of Ocean Science for Sustainable Development (2021-2030) and calls for an increase in scientific knowledge of the ocean to support the sustainable management of marine resources and development of the blue economy. 

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Gap analysis of bathymetric data coverage in the U.S. exclusive economic zone (coverage indicated in purple).

Here in U.S. waters, we are working to help fill these gaps by supporting the Seabed 2030 initiative and maximizing the societal value of the data that is collected. Using multibeam echo sounders that survey large swaths of the ocean floor, we can collect a tremendous volume of bathymetry data along with water column and acoustic backscatter data aiding in habitat mapping. There is also increasing activity in seabed mapping to support offshore wind development and seabed minerals mining. Further, we are working with partners, state and federal agencies, and citizen science and crowdsourced programs to coordinate the collection and sharing of data. These efforts enable us to work toward increasing the breadth of data collection by covering an expanded geographic scope but also the depth of data by collecting data beyond simply bathymetry.

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Rear Adm. Shep Smith (while serving as commanding officer of NOAA Ship Thomas Jefferson) discusses bathymetric data collection with Erin Weller, a physical scientist with Coast Survey.

Zooming in from the global scale to individual ports, our focus changes. Our concern is no longer building a baseline dataset for longer-term research needs but getting ships in and out of port in the safest and most efficient way possible. Based on the success of the Long Beach pilot project, NOAA offices involved with precision navigation were awarded additional funding to support foundational program management, and established a dedicated team to support the expansion of precision navigation to more ports throughout the country in the coming years. 

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View from the M/V Ocean Wind as the ship transits down the Mississippi River. This region is the most congested waterway in the world as more than 10,000 ships pass through the port complexes between New Orleans to Baton Rouge each year. Plans are underway to implement precision navigation in the Lower Mississippi River Port Complex as well as in the Port of New York/New Jersey.

Whether working on the building blocks of a global high resolution bathymetric data set or customizing precision navigation port-by-port, the key to success is standardization. The latest edition of the International Hydrographic Organization’s (IHO) S-100 framework—increased standardization of maritime data products—will be published this December. NOAA plans to develop new services in line with these new standards, which will begin a new era in electronic navigation. 

It is an interesting time in our field. We are still learning, still discovering, still building. We are working every day toward mapping the ocean and developing precision navigation for our major ports. The global community first recognized World Hydrography Day in 2005 when the United Nations General Assembly adopted Resolution A/60/30. We have made a lot of progress in the past 13 years. In another 13 year’s time, we will have just surpassed the 2030 mark. I anticipate that by that time, we will be able to review with pride both our improved understanding of the ocean and sustainable growth of our blue economy.


We are celebrating World Hydrography Day all week! Check our website to see new hydrography- and bathymetry-related stories added each day.

New NOAA precision navigation program increases safety, efficiency for maritime commerce

By Capt. Liz Kretovic, Deputy Hydrographer of the Office of Coast Survey

Nowadays, many cars have sensors, video cameras, and other technology installed to help drivers park in tight spaces. Now imagine you are trying to parallel park a tractor-trailer on an icy hill, against a strong crosswind, with millions of dollars of products that depend on your precise execution. Dynamic conditions, tight spaces, and high stakes are exactly the scenario that many commercial vessels face as they move 95 percent of the United States’ foreign trade in and out of U.S. ports and waterways. In a manner comparable to the way car technology supports drivers, NOAA has launched a new program to develop the next generation of marine navigation tools that provide mariners with the information they need to safely and efficiently transport maritime commerce. This next generation of products is referred to as precision navigation.

Mariners face complex decisions as ever-larger vessels make their way through congested U.S. ports.
Mariners face complex decisions as ever-larger vessels make their way through congested U.S. ports.

Precision navigation seamlessly integrates high-resolution bathymetry with real-time and forecast data—such as water levels, currents, salinity, temperature, and precipitation—to produce a stronger decision support tool. As a result, mariners are better equipped to make critical go/no-go decisions. Since precision navigation involves many types and sources of data, it is a well coordinated effort across several NOAA offices, including the Office of Coast Survey, the Center for Operational Oceanographic Products and Services, the National Geodetic Service, the U.S. Integrated Ocean Observing System, and the National Weather Service.

This year, NOAA offices involved with precision navigation were awarded additional funding to support foundational program management, and have established a dedicated team that will support the expansion of precision navigation to more ports throughout the country in the coming years. The precision navigation program team includes a program manager, requirements coordinator, and dissemination manager, as well as members from the other involved NOAA offices. In addition, the funding will support a socio-economic study that will look at the return on investment of the precision navigation program and fund a developer to work on the dissemination of NOAA’s data with private industries. Plans are underway to implement precision navigation in the Lower Mississippi River Port Complex as well as in the Port of New York/New Jersey. The program is currently developing a stakeholder engagement strategy to determine needs that can be addressed by precision navigation in these ports.

These new initiatives build on the success of a demonstration project in the Port of Los Angeles/Long Beach, where NOAA and its partners created high resolution depth maps and improved wave prediction, and combined them with water levels from the Physical Oceanographic Real-Time System (PORTS®).  The improved services, integrated into commercial navigation software packages, allowed the port to increase the maximum draft of tankers from 65 feet to 69 feet. Each extra foot of draft translates to an additional $2 million of product per tanker transit. In addition, the increased draft allowance decreased lightering, which saves shippers an estimated $10 million per year. Expanding precision navigation to other high volume ports will reap additional economic benefits for the nation. Private industry beneficiaries of precision navigation include sectors such as the oil and gas industry, port authorities, shipping, fisheries, agriculture, and intermodal transportation networks.

The new NOAA program highlights the importance of public-private partnerships in improving the U.S. maritime transportation system. Precision navigation greatly improves safety and efficiency within the maritime community by reducing the risk of collisions and groundings while allowing vessels carry more goods in a single transit, which means fewer total trips. These benefits to maritime safety, the environment, and the economy will continue to grow as the precision navigation program brings this decision support tool to more ports around the country.

First U.S. federal channel using USACE survey data receives improved quality classification from NOAA

By Rachel Medley

The U.S. federal channel in the Delaware Bay is vital to maritime commerce, leading deep draft vessel traffic to and from the major ports of Wilmington, Delaware,  Philadelphia, Pennsylvania, and Camden, New Jersey. To navigate this federally maintained waterway safely and efficiently, mariners rely on the surveyed depths displayed on nautical charts. The U.S. Army Corps of Engineers (USACE) Philadelphia District regularly surveys this area, utilizing sophisticated techniques and equipment to map the depths of the seafloor. NOAA’s Office of Coast Survey, in turn, adds quality classifications to these channel depths and displays them on the nautical chart.

The portion of the federal channel from Newbold Channel Range down to the mouth of the Delaware Bay is the first waterway in the U.S. to have an improved quality classification assigned to USACE survey data—category of zone of confidence (CATZOC)  A2. Improving survey quality and upgrading the CATZOC classification allows operators to accommodate smaller margins of error while still ensuring that navigating maritime approaches and constrained environments remain safe. These decreased tolerances allow ships to maximize their loads, ultimately increasing inbound and outbound cargoes.

“This is a huge leap forward toward the sophistication of nautical charts, and will help the maritime sector along the Delaware River. I want to commend the men and women at NOAA’s Office of Coast Survey and the Army Corps of Engineers District Philadelphia for working together to provide safer timely high-quality data for maritime commerce. I applaud Commerce Secretary Ross for recognizing the vital role that NOAA’s Coast Survey provides to the maritime industry and thank him for this outcome. This synergy between NOAA and the Army Corps is exciting to see, and I support efforts to replicate this pilot project in other ports and waterways around the country.”

  • U.S. Senator Chris Coons (D-DE)
View of the Delaware River from MSC Gayane outbound off Fort Miffilin Range.
View of the Delaware River from MSC Gayane outbound off Fort Mifflin Range. Credit: Captain J. Stuart Griffin, Mariners’ Advisory Committee Chairman (MAC) and Delaware River and Bay Pilot.

Allowing additional draft. What’s it worth?

Upgrading how NOAA encodes USACE channel depth data reduces additional safety margins applied to the draft of large ships during transit and berthing operations. The USACE District Philadelphia is in the process of deepening the Delaware River from Philadelphia to the sea, with a controlling depth in the federal channel from 40 feet to 45 feet (from Beckett Street Terminal north the channel remains authorized at 40 feet). Every foot of draft represents a significant dollar amount in the shipping industry depending on the type of cargo the ship is carrying. For instance in Long Beach, California, for every extra foot of draft allowed by the port, tank vessels can add $2 million of extra product. As ships load cargo, the draft of the ship increases—in the case of the Delaware River, the draft cannot exceed the 45-foot controlling depth (once USACE completes dredging) or the ship will run aground.

Shipping companies and insurance underwriters determine the maximum draft allowed for a vessel during transits of waterways in U.S. ports, adding a margin of error to the draft for safety. In some cases a safety margin of 25-30% may be added, ultimately resulting in dollars lost for the shipping and terminal operators. Not to mention, negating the expense and time involved in dredging a channel. The navigational tolerances are determined using guidelines that include the known quality of survey data in a particular waterway. The better the quality of the survey, the lower the risk associated with the ship transit, resulting in additional cargo loading per transit.

What is CATZOC?

Survey data within an electronic navigation chart (ENC) is encoded with a data quality indication known as CATZOC. CATZOC quality helps the mariner determine the accuracy of charted conditions on the seafloor at the time of the last survey. In particular, the mariner should understand that nautical chart data, especially when displayed on navigation systems and mobile apps, possess inherent accuracy limitations. CATZOC quality designations, A1-D, are the specifications that were met at the time of the survey.

Currently all federal channels are designated as a CATZOC B if the USACE has collected the data. This a recent development as previously all federal channels were designated as a CATZOC ‘U’ for Unassessed. Rear Adm. Shep Smith, Director of NOAA’s Office of Coast Survey, was asked by Intertanko, a maritime association that represents the interests of the tanker industry, to remove the ‘U’ designation on ENCs as it was impeding the industry’s ability to do a proper risk model assessment of ships entering U.S. ports. Nationwide, the USACE is the federal authority for maintaining federal channels; NOAA does not normally assess USACE surveys and as such designated all surveys as a CATZOC B.

USACE survey techniques factor into CATZOC quality

The maintenance of all federal channels falls under the jurisdiction of the USACE, and as such, Coast Survey recognizes the USACE as the authority for survey data acquired in these active waterways. USACE districts around the country help the flow of commerce in and out of the nation’s busiest ports and Coast Survey applies data from 22 of these districts to nautical charts for safe navigation by deep draft vessels. The USACE districts use sonar equipment to measure sediment movement within the channel to maintain channel-controlling depths and determine dredging needs.

The USACE Philadelphia District is unique in that it is fully utilizing its multibeam sonar equipment, which has the capacity to survey large swaths of the seafloor and detect features and obstructions that might be harmful to deep draft vessels. As vessels in the nation’s waterways continue to grow in size, USACE districts that are utilizing their multibeam systems are helping to ensure that the general bathymetry of the seafloor bottom is well known at the time of the survey. This is particularly important as vessel drafts are nearing the seafloor bottom in port areas across the country, running higher risk of hitting a feature or object in the waterway.

“The Delaware River port community is taking steps to utilize the planned deepening of the main channel.  We are already seeing arrivals of post-Panamax sized vessels that require special transit considerations and planning. Our valued partnerships with USCG, USACE, and NOAA are critical to the safe movement of deep-draft commercial traffic in our waterway. As the USACE nears completion of the project to deepen the main shipping channel, improvements in sounding data quality have enabled NOAA to provide safety assurances to shippers in the form of improved CATZOC designation for the estuary. This has real-world relevance to ship owners and charterers who move vessels on the Delaware and will allow them to more effectively utilize the full channel depth upon completion of the deepening project.”

  • Capt. J. Stuart Griffin, Chair of the Mariners’ Advisory Committee (MAC) and Delaware River & Bay Pilot

Updating NOAA nautical charts

Coast Survey is exploring various ways of changing and improving charted information for the mariner as outlined in the National Charting Plan. Coast Survey is working with USACE Philadelphia District to determine the CATZOC quality of the survey data acquired in the Delaware River. The CATZOC value of the surveys collected over the past year by USACE District Philadelphia have been designated by Coast Survey as meeting a CATZOC A2 standard. There is a significant improvement in survey quality designation from a CATZOC B to a CATZOC A2. CATZOC A2 seafloor coverage indicates that the full area was surveyed and allows for the detection of significant seafloor features. CATZOC B seafloor coverage does not have sufficient quality or resolution, indicating that while hazardous objects are not expected, they may exist and may be undetected because of the survey quality.

Coast Survey has encoded ENCs with the CATZOC A2 quality in portions of the federal channel along the Delaware River that are surveyed by the USACE District Philadelphia utilizing robust multibeam survey methods. There is not a refresh rate or time frame required with international CATZOC standards, however, USACE Philadelphia District typically resurveys the main navigation channel on an annual basis using the same multibeam survey techniques that NOAA used to assess the current CATZOC value.

Potential impact to shipping companies and terminal operators

For the portion of the federal navigation channel from Newbold Channel Range down to the mouth of the Delaware Bay, this designation will decrease the risk margin placed on ships transiting the waterway and make fuller use of the actual controlling depths in this waterway.  Additionally, “this could potentially help to lessen the expense and risk of lightering operations,” reports Eric Clarke, marine operations cargomaster at Philadelphia Energy Solutions.  Commonly, shipping companies whose risk models are calculated using the CATZOC B quality levels mandate lightering operations before transiting to terminals where water depths are more restrictive.

Through coordination efforts between USACE Districts and Coast Survey, federal agencies are working to serve up better data and information to the mariner so they can make more informed decisions to keep commerce moving effectively and safely in the nation’s busiest waterways.


The author, Rachel Medley, is chief of the Customer Affairs Branch at NOAA’s Office of Coast Survey. She also serves as the NOAA liaison to the Delaware River and Bay for navigation issues. For more information, please contact Rachel.Medley@noaa.gov