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 Submarine Base Bangor 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.